What to do if drain plug is stripped cannot take off with wrench

I'd try drilling it out... but do so with the item it's in upside down (so that the drain plug is pointing directly downwards so that no pieces of it will fall into the oil reservoir).

Hang tight, though. There are a few others more knowledgeable than I in this area who frequent this board.

PS. If the plug is metal, then a large screw extractor might work also.

If just the hex on the drain plug is rounded off, try a pipe wrench for a better grip. Remember lefty-loosy, and righty-tighty.

what to do if drain plug is stripped cannot take off with wrench
Get hold of it with a pair of vise grips and get it out first. Then go to the parts store and get a replacement for it.

Whak the end firmly (without breaking), this will generally loosen any bolt. Then you should be able to loosen

If the bolt just turns and doesn't thread out I would try to wedge something between it and the head of the bolt. Then with slight pressure pulling the bolt head down away from the housing, try to turn it with a wrench. The last thing you want to do is damage the housing.