I am going to be changing my Diff fluid for the first time and the manual i have says to remove the drain plug on the bottom of the differential, only i don't have a plug at the bottom of my diff. They have a pic of the diff in the manual and where its SUPPOSED to be, but mine is completely blocked off. I have the correct year and model but it doesn't look the same, do i just need to unbolt the diff cover, clean gasket surfaces, install new gasket, bolt it back on and fill or am i missing something in there?

 

Yep just unbolt the cover make a mess, clean it up, put it back together and refill.

 

what do i need to use to clean off the gasket surface, will a regular ol putty knife do?

 

Putty knife should do ok. Maybe a razor blade if stuff's really stuck on there. Just try not to gouge the gasket mounting surface. I also like to use a mild abrasive pad with my die grinder to clean the mounting surface.