This is THE thread on p18/FKS brake bending: http://www.tetongravity.com/forums/showthread.php?t=24647
(or search Google for P18 Wide brakes).
I've used the first method myself and it wasn't too bad. If you've got a solid vice, old ski pole and a few screwdrivers then go for it. Just BEND SLOWLY and you'll be fine. Do one at a time so that you can see how it goes bac ktogether. The only tricky part is getting everything back together, the spring particularly. I put it in first and it's a royal pain in the ass. I have some 155s of my own to do so I think I'll try tapping it in last like some people in that thread say, and it's meant to be easier.
Check the last page of that thread too for an alternative method that doesn't involve taking the binding apart, but I think you could screw up because it'll stress the middle part of the brake piece. I've read some people (team managers even, I think) just mount the binding, crank the DIN, snap a boot in then bend straight and re-bend. I thin kthat'll stress the same place though.