When I did mine I found a dremmel or equivalent with a cutting disk the best way of getting the old crimped clamps off the injectors once they were out of the car. When you put the replacement hose clamps on don't tighten them all the way up, leave about 1 or 2 mm gap on the clamp thread. You should also replace the injector rubber rings as well while you are at it as they harden over time and can cause a vacumm leak.