How should I remove a tyre that's stuck to the rim with old sealant? I have a wheel with a puncture. It seems to be a pinch flat (the air is shooting out in the direction of the rim) but I can't get the tyre off to investigate.

This is an ex-tubeless tyre that I put a tube in once. Guess I should have cleaned up the sealant first. Now I can't even move the tyre, let alone remove it.

The rim is aluminium. Is there a powerful solvent that is safe to use, that would weaken the old Stan's + muck glue?

I googled around this, and most answers are 'be a man! use tyre levers! No, they're for girls, use your thumbs!'. 

Well, I'm beat. I have poor muscle tone and bad motor skills for medical reasons, so I accept the possibility that 'normal' people could just pull it off. I, however, can't. The suggestion here was use a credit card but that didn't work.

I could take it to the bike shop, but something tells me this isn't the last time something like this will happen. I'd like a solution for next time. I need a solvent that won't attack the aluminium. Ideally I'd like to save the tyre/tube, but that's a bonus.

Edit: whoever suggested a vice, that worked. It unstuck the tyre and I could remove it normally with tyre levers.
Before looking for a product to solve the problem, try this. Many tubeless rims grip the tire very tightly when one is just trying to push the tire very inwards to unseat it. The trick is often to push the bead section more straight down in the direction of the rim well, with a slight scooping motion inward.

Sealant isn't glue and doesn't have all that much tensile strength. It's usually the case that you're more up against the mechanics of how the bead locks in place.