im changing out a rear bearing and oil seal on the rear axle. it has c-clips

There are 2 tings to try first. Use a long pick and try to unscrew the piece that is still in the differential. Most of the time there is only 1/2 to 1 thread left and it will come out very easily. The second option is to drill it out. There is a special tool kit designed to drill it out. Snap-on, Matco, Etc all make it.