Plastic scraper if it's really thick and goopy to get the bulk.
Then paper towels to get the heavy buildup.
Then shop towels (the red ones at Harbor Freight are great for this) with some sort of solvent. Naphta, kerosene, mineral spirits etc. WD-40 works great too, but it's more expensive (unless you're like me and have 4 bottles because you keep misplacing them in the shop, garage, kitchen cabinet etc.).
Also, pour the solvent into a small container. Don't put a dirty rag against the mouth of the big container, unless you use that solvent only for cleanup (and not for thinning finishes)
Q-tips for hard to get places.
As Bernhard said, plenty of ventilation. A respirator is also a good idea.