So I have a Saiga 12 and I want convert it to a left side charging handle. To do so I have to cut the left side of the top cover to expose the left side of the bolt.

I am trying to decide what to use to cut the cover. I want to make the lines as clean as possible, and an idea I had was to clamp a piece of 1/8in thick 10in x 1in steel to the top cover (long ways)using it to guide the dremel. Its thin metal so it wont take much to cut it, just want it to be clean.

any one got a better idea?