I forgot to add:
- Get a hole tap to make a dent in the center.
- I ALWAYS use a 1/8" drill to start the hole, then I move it a bigger one or the step drill bit.
I use metric step-down bits on a hand drill and use clamps to hold down the enclosure. Be careful as the bit will get caught and the enclosure will get away from you.
When I drill I always make them smaller and have parts to check fit (don't use all the same parts), or have a paper template...