You can use a dremel on steel, but it's an incredible pain in the ass. I'd suggest getting a cheap $20 wired drill and a hole saw. Also get some cutting oil for the job, which will make the job much easier and cleaner. Galvanized Yankee can give you a lot more pointers on this than I. Me, I was kind of in the same boat, but I didn't want to mess up my case, so I go out in town and get the work done. I go to a stainless steel shop in Corpus Christi, and I got three holes done for $36. ANd the job was so much better than what I could ever do. Yes, it kind of might be cheating, but oh well. The quality of the cuts was worth it. Good luck, and welcome to the forums.