Drive around for a bit so that the tips heat up and expand.
Spray some WD-40 or the like.
Wear some heavy duty gloves.
I use a small 10" "crow-bar" and insert directly into the tip as far in as possible.
(I can take a pic of it if you want - I got it at Home Depot.)
Start yanking.
If that doesn't work, try pushing the res tip in, then yanking out hard and fast. This will give you some momentum to get them all the way out.
Tip: Once they are out, use a small hammer and make the circumfrence of the res tip smaller so that they are not such a PITA to remove next time.
HTH
