I have a 3" PVC closet flange in my basement that is mounted to the cement floor and the flange is cracked in several spots and leaking. How can i repair it without breaking up the cement floor, is there away that i can remove the top of the flange and insert a new one.

speedball1

Once PVC has been glued it's glued forever. Ya don't just "remove it" ya cut it out. So unless you want to tear up the cement and reconfigure the stubup to accept a new flange we better be looking at repairing the old one.
While you didn't tell me where the flange was cracked but it usually happens at the slots, and these are cracked on a PVC flange because of overtightening the closet bolts holding the bowl. They make flange repair kits, (see image) that slip under the cracked slots and that's the way I would go. Good luck, Tom