I dont think hammering them in was a good idea in the first place when you saw they didnt fit... but this happened once to me I just took a hammer and flat screwdriver, put the screwdriver diagonnaly in the clamp indentation (you know that little cut at the bottom of the steertube, I forgot the name its really stupid I know but I just cant remember it) and I hammered it on one side to try and strech the indentation wider and reduce the grip on the fork. then I just wiggled them out. It worked for me it should work for you.