Don't shove a piece of anything in there and pop it off that way. Use the correct puller or a bolt and hydraulic with water. Just had a thread on another forum I'm on where the rod the guy used bent and wedged in there and had to cut his $500 clutch off and then have the threads redone on his crank. The same puller works on all the XP's from 09 to 14.
What do you need to pull primary off for?