you wont have to bend at all. 3mm difference is only 1.5mm on each side (less than 1/16" for you yanks). in my experience, you're generally fine with about a 10mm wider ski than brakes and if they're just catching a little bit, you can shave a mm or two off of the inside of the plastic on the bottom of the brake. fks brakes are pretty easy to bend too, the hard part is just reassembling the heel assembly and getting the spring back in.