So I pretty much never post to forums so forgive me if I am breaking some rules or in the wrong thread, however there is almost no information on doing this mod with the Kraken G12 at the time of writing this so I thought I would share in case it will help anyone attempting the same thing. Keep in mind that everyone's setup is different, so I'm not responsible if you attempt this and break something. I recently stepped up to an EVGA 1080 TI FE and love the card (thanks EVGA) but was pretty underwhelmed with the thermals, and since the EVGA mod is still unavailable I decided to use the new Kraken g12 with a Corsair h90 to remedy this. Here is the finished product (Ignore the messy wiring, I will deal with that later).
I didn't originally plan on doing a write up so I don't have any pictures of the tear-down, however I recommend checking out the Gamer's Nexus video on youtube for the 1080 TI FE for a guide on removing the cooler in one piece. Once I had my card down to the PCB, I placed my stock thermal pads back on the old cooler, removed the old thermal paste from the GPU, and began installing my own heatsinks onto the card. You may be able to get away with not using heatsinks at all since the G12 has a fan for this purpose and the VRM components can handle alot of heat, but I decided to be cautious and use them anyway. I used arctic thermal pads from amazon, (One 50mmx50mmx1mm and One 50mmx50mmx.5mm sheet) and two packs of VRAM heatsinks (8 pack) and one pack of FET heatsinks (20 pack) but I would recommend getting two instead since I didn't have enough to put one on every component. I removed the adhesive from the bottom of the heatsinks and cleaned off any residue with 90% rubbing alcohol, then cut the Arctic thermal pads to size, using the 1mm pads for the VRAM heatsinks and .5mm for the FET heatsinks. The thermal tape that comes with the heatsinks may be sufficient, but there was no information on its conductivity so I opted to replace it. Something to remember is to be careful not to short anything out with the metal heatsinks, I made sure that the thermal pads were covering the entire bottom of the heatsink to prevent this. Make sure to firmly press your heatsinks on so that they don't fall off as well, and clean off any residue from the old thermal pads as it will prevent the new ones from sticking.
Once you have the heatsinks on your VRM and VRAM, you can install the G12 mounting bracket, which conveniently just clears the VRAM heatsinks I used, and apply a thin layer of thermal paste over the GPU die. I used Arctic MX-4 as it is not electrically conductive which will keep you from frying your card if paste gets on any exposed circuitry. Since the GPU doesn't have an IHS like a CPU, I would not recommend the pea method as you want full coverage and spillover is not as big of a deal.
The G12 includes two foam spacers that its instructions will tell you to apply to the bracket before mounting it to the card, but I found that they put an unnecessarily high amount of strain on the PCB in my setup (almost to the point of causing damage) and I personally recommend leaving them out on this specific card unless your components are touching the G12 somehow. I then attached the h90 pump/coldplate to the g12, and then attached the G12 to the mounting bracket on the card, and was careful to tighten it evenly so that the coldplate was flush with the GPU. DO NOT tighten the screws until they stop or you run the risk of cracking your GPU die, you just want the screws to be snug and evenly tight. If the coldplate looks crooked or the screws are unevenly tightened, I recommend backing them out until they barely catch the threads and slowly tightening them a couple turns at a time in a star pattern. Once your G12/pump is mounted to the card, you're ready to install it, but you could reinstall the backplate at this point if you wanted, however you would need to find some nuts to use on the screws that secured the old cooler, as the backplate screws thread into them.
I don't have any pictures of the card assembled outside of the case or of installing it, as I didn't plan on doing a write up, but make sure before hand that you will be able to fit the components in your case, as my huge Cryorig R1 prevented me from mounting my radiator as a top or rear exhaust as I had originally planned, and I was forced to mount it to the front intake fans using XSPC radiator mounts I had bought from Amazon, which is definitely not an ideal setup. This probably would have been adverted had I bought an NZXT cooler instead as they have 16" hoses opposed to the usual 12" hoses on other Asetek AIO's, but I wanted Corsair's 5 year warranty and the H90 is cheaper than an x42 or x41.
After I connected the pump, radiator fan, and G12 fan to the MOBO and powered it on, I was relieved to find that I didn't brick my card, and that it was now Idling at 30C as opposed to the 41C I was getting on the stock cooler. Under load I am now getting a new max temp of 43C on the GPU (Edit:seeing 48-50c once the loop heats up) vs the stock cooler's 70C at 80% fan. I was going to attach some pictures of GPU-z and Precision X here to show the temps but it won't let me upload more than four pictures for some reason so I may add a follow up post with pictures of temperatures if people care about that. I know a big concern of most people that consider going this route is whether or not the G10/G12's fan will properly cool the VRM in the absence of the stock midplate, but with my IR thermometer I found that the VRM and VRAM were not exceeding 40C under load, and that there was only one hot spot on the back of the PCB where the VRM is located that reached 52C, which is still within acceptable ranges. Its worth mentioning that most reports of high VRM temperatures with the G10 seemed to be a result of the tester using Furmark, which I refuse to run as its an unrealistic test and I don't want to kill my card for no reason. Once again, I can try to follow up with more pictures of the temperatures but this was all I could get to upload.
Here is the hottest point I could find on the card on either side while under load.
All in all I would still recommend getting a card with better air cooling rather than converting a Founders Edition like I did, but if you already have a Founders Edition and think that this looks like too much work I would instead recommend getting the EVGA hybrid kit if it is ever available. However if you want a radiator bigger than 120mm for your 1080 Ti FE and don't mind some extra work, a G10/G12 and AIO combo is definitely a viable option. Also keep in mind that doing this will probably void your warranty so don't attempt this if you can't afford to replace your card in a worst case scenario.
Edit:Having hard time adding pictures? Am I doing something wrong?