ROM Hack How can I mod levels on 3DS platformers?

[PkStarzone]

Basically, I want to modify levels from 3DS games, more speficially Sonic Lost World. For the moment just add small edits like removing enemies and move existing objects. But eventually I would like to import brand new levels.

I know it's possible to make level mods on games like Super Mario 3D Land. But I have no idea how and how to do that in Sonic Lost World.