You could buy a complete Dremel kit for under $30 if you want to make it really finished and perfect. Heck, Harborfreight.com sells them for $6, but you get what you pay for.

Also you could use a drill to make relief holes, and then tin snips to cut between them. File your edges when you're done, and paint never hurt anyone. I reccommend you paint any exposed metal because it WILL rust.