[Invasian]

So just got my first demel to ensure proper fitting on my Detonator Costa slide on my TM M&P, as it stands it won't cycle all the way back and i can clearly see that i need to dremel the slide so that it would.

Questions as follows:

1)Do i dremel the bottom of the slide first or the inside of the slide first?
2)What bit do you guys recommend i use ?

First time doing this on my own and needless to say I don't want to fuck it up.

Any advice would be greatly appreciated.

cheers,

J