What Joe said & there is a retrieval tool for this which likely has hooks that will catch the snap ring for a secure grip. if no varnish on the sides which I dont think is the case here it oughta be trouble free. If new lifters are going back in the hard part is gonna be getting some breakin lube on the bottoms & not close to the edges where it could get on the sides & hinder rotation & hit the hole dead on with the new ones.