How to copy a main level to editor
Sorry, but as far as I know, you just cannot copy them. U need to memorise them or check every one block of your level if you want to copy them. The level TOE 2(insane player-created level) is a good imitation of TOE 2 (the main level), but some rings are not in the same place. Whether to make it easier or what, I do not know but I dont think you can copy a main level.
The only way to copy a normal level is to find copyables of it, kinda sad that you can't copy them, but at least people create copyables!