How to loosen jointer gib screw with worn head...need help NOW.

[hairy]

Hmm, interesting! Not sure if it would work at undoing a stripped nut if you can't access the top of that nut, but I'll definitely look this up again should I need to remove any screws from the top.

Try some anti sieze compound on the new screws.  

https://www.amazon.com/s/?ie=UTF8&keywor...txxs_e_p20

If nuts and bolt heads are getting stripped when you try to remove them, it's either corroded or installed too tight. Most manufacturers install hard ware dry, that's never a good idea if you want to remove them.

[fredhargis]

Glad it's resolved. Hairy's advice about the anti seize is good...be sure to do that with the new bolts.