here is how to install the evga backplate with ek waterblock.
1. you will need to increase all of the backplate hole size using a 3.5mm diameter drill bit. Use a HSS bit for better and smooth results.
2. you need two 8mm M3 screws with nuts and some 6mm M3 screws.
Pics below.
Green =M3 x 8mm screws with nuts.
Red =Ek supplied screws with washers.
Yellow =M3 x 6mm screws.