i learnt this the hard way i was doing a timming belt on a 1.8 d fiesta. i bent the pin right around the back of the camshaft sprocket. i ended up taking the sprocket of the shaft and stupidly handed it to the apprentice to remove.he got the pin out for me but he didnt use soft jaws in the vice or a copper hammer.so he had to spend another hour dressing it up with a file