Prepare the Case
The circled structures should be removed. I use the cut-off wheel to take off most of the piece and then follow up with a barrel stone to grind it flat.


These parts are a bit more tricky. The raised lip around the battery door should be removed but be careful not to cut too deep or it will show and keep the battery door from fitting correctly when you're done.

The upper left gap is explained more fully in the next frame. The upper right gap usually needs to be widened but you'll have to see how the leg fits before you know how much.


This picture shows the corner after one pass with the cut-off wheel. Now switch to the steel cutter and carefully ream out the gap (circled).


All done (for now).