I've always gotten great info and tips lurking around Stunthangar, so thanks to you all for this excellent resource. Inspired by all of that knowledge here's a trick I used to remove a stubborn Wristpin from a ST46.
I began by trying to remove the pin using the ST needle and it wouldn't budge and then repeatedly after the following steps:
I filled up the backside of the piston with carb cleaner and soaked overnight - no joy.
Heated up the backside with blow torch - nothing
Filled up the backside of the piston with PB blaster and soaked overnight - nope
Torch again - nope
Popped it in the oven - Dang! now the wristpin-pad popped out. Now what?

Well here's how I got it out.

• Wrap a small piece of paper towel around a toothpick and soak in acetone and use it to clean out the wrist pin barrel.
• Scuff the inside of the Wristpin barrel with the micro Dremel engraving bit
• Scuff the end of a piece of 1/8" steel wire using the Dremel cut-off tool
• Apply JB weld to the steel wire and stuff it in the wristpin barrel. Remove excess JB weld that oozes out of the barrel using a toothpick
• Allow the JB weld to set for at least 12 hours
• Squirt a shot of PB blaster on the underside of the piston to soak the pin
• Now jiggle the steel wire clockwise and anticlockwise a quarter turn while slowing pulling out the pin
• Voila!
• Now to remove wire from the pin - clamp the wire tightly in a vice and prize off the pin off by leveraging it off the vice with an adjustable wrench
• Voila!

I've attached some pics of the sequence.

I hope you find this useful if you ever happen to need it.

 

Great Job Damian. I have had trouble with those also, and your way will be what I try next time. I had one that I just could not get out. Like you, I tried heat and PB Blaster, and nothing worked. I finally drilled a small hole in the front of the case to push the pin out. I then tapped the hole and cut a bolt down to fit in the short space of the case without hitting the sleeve. Thanks for the pictures as they are a great help.