A Dremel-like rotary tool is not the tool for this job. You could do it, but you'll learn to hate yourself and the rotary tool way, way before you finish. Your least expensive solution for this, would be to buy the cheapest 4.5-inch angle grinder you can find (maybe $20, less on sale at Harbor Freight), and a couple wheels, and have at it. Despite how cheap they are, if you don't insist on pushing them until they overheat (which your rotary tool will, really quickly), they last a surprisingly long time and are a great value for the money. ... as a semi-aside, you can get a reasonably accurate comparison between how fast two different tools can remove metal, by comparing the watts or amps rating. To a first approximation, there's a direct, pretty much linear relationship between watts and metal removal rate. If your rotary tool sucks up 1/5 the power that an angle grinder does, it'll remove metal roughly 1/5th as fast. A super-cheap angle grinder might be 5.5 amps, and a good one might be twice that, and the good one will knock metal down twice as fast as the cheaper one (or remain much cooler at the same metal removal rate). More on reddit.com

Here is a list of the different types of rotary tool bits and what they are used for. More on reddit.com

I find that like almost all tool “kits”, they are full of 80% things that you will never even look at and maybe 20% useful things. So now I just buy individual Dremel brand bits based on need. More on reddit.com

McMaster-carr has a decent set. Not sure of the brand. More on reddit.com