Do you have any tip removal or pool cue re-tipping tools?
Here's what I do. I take a razor blade with my tip on a block of wood as not to scratch anything important, and I cut the tip off leaving about 1/8 inch of the tip left.
I get my sander out and onto my shaft in place for "shaving" the tip. The sander has coarse sandpaper on it to make it quick, then once my tip is almost gone, I change the sandpaper to a really fine grit sandpaper to finish it off without sanding away a lot of the ferrule once the tip is gone.
Inside the clamp that goes onto the shaft, I place a penny roll as not to scratch my shaft while doing it.
This sander can be found at Muellers, and it is less than $20, with sandpaper refills being about $5 I think.
If I don't feel like doing this, and usually I don't, I just run my shaft down to Bob DZ and let him change it for me. He's only about 10 minutes away from me!