stripped threads

I foolishly over-tightened and stripped the threads on transmission fill plug on 2010 Sportsman 550 X2. Cannot remove plug (just spinning). Any suggestion as to how to get the plug out; and how to repair damage? Friend recommended prying plug out and using a Timesert repair kit to replace the...

I changed the rear differential oil in my 2005 500 HO and over torqued the plug stripping the threads out of the rear housing. Does anyone have a fix for this problem? What looked like a relatively simple job is turning into a nightmare. Any and all suggestions are appreciated....