Short the pads outlined in white with solder. The one above the cpu is a resistor so you can either just solder across it (or use conductive ink, your choice) or remove it and then short the pads.
 
Mod for the E757 Rev. 1.0:
Above cpu:


Top-right of northbridge:

 
 

Any Update on how it went? About to attempt this myself. 

I've got an x5650 coming I'll post back when I've had a chance to try it. And when you talk about the resistor mod are you talking about this mod [can't post links....]

I just did the mod to use a X5687 because I acquired two of them out of a Dell Precision that died.  It worked, sort of.  It posts and boots Windows and seems stable, but the CPU fan header doesn't work and the BIOS reads the CPU temp very wrong.  It thinks it's about 11C when it should be 30C.  But I don't know if those issues were pre-existing or not.

I did the mod recently on a E758 for a Xeon X5680 

tyneu23
Awesome, so people are still doing this mod . @mbeutler did you have to do both the solder mods or did just the one by the North bridge work?

I did both, but after some troubleshooting I don't think the one near the CPU is necessary or advised.   I confirmed with my voltmeter that it connects to the CPU fan header, so I think it needs that resistor to report the correct CPU temp and activate the fan.  Without it, the bios only shows 10C which is impossible.
 

tyneu23
@mbeutlet would you be able to post the pics of the aftermath of the physical mod on the MB??

No one wants to see my solder work.  These pads are tiny and I'm not very good.  I started by using some stripped cat 5e wire to jump the pads, but made a 2nd attempt and got them bridged with just solder.  However, I need to get the resister back in place near the CPU and haven't been able to do it without tweezers.

I did the mod .... no post.. its now showing code 68 rather than FF at least i think thats progress.. i wonder if it has to be at the latest bios

Hey, i just did the mod. Its working, but i cant set the vcore voltage. You talked about a resistor mod for the E758, which you applied to the E757. Where can i find the resistors that i have to mod on the E757? I really need the voltages for overclocking. I would be so grateful when someone could help me!!

It's been a while so I'm not certain of what I did to make the voltage work. Try undoing the mod above the socket first and see if it still boots. 
 
This is what I was referring to with the e758 mod (basically move the resistor instead of shorting):
But if it's working then don't worry about it.