Dipstick tube removal. Ideas?

Do you have a piece of metal round stock that will fit inside the tube? If you do, turn the block over and spray some PB Blaster or equivalent on it and let it sit for a bit, slide the round stock in the tube down as far as you can, that will help keep the tube from collapsing when you grab it with some grips. Grab it as close to the block as possible and try slowly working it back and forth in a rotational motion to break it loose.

A little heat might help too, propane torch.