Get the shop to do it, it saves time, especially if you don't do it that often. However, if you DO do it that often, what you need is a vice, the top half of an old ski pole, and a torch (not really necessary, but some people think it is). You put the brake in the vice, put the (hollow) pole around the brake foot and use it as a lever to make one side of it straight. Then move it in about 5mm on the vice (measure) and bend it down again. Heat makes it easier to bend. Then repeat for the other side. 5mm on each side will actually give you a bit more than 10mm extra clearance because of the bend. And for future reference, the TGR forum url is
www.tetongravity.com/forums