Switch maps like, going to a map you downloaded?!
That's usually not very difficult. When you downloaded everything, just copy the files and paste them into your 'exports' folder. That folder can be found in C:FeralHeart > exports. If you're logged in the game while doing that, just restart.
If you don't know where the portals to downloaded maps are, go to the
'Cape of distant worlds' and they should be there.
Hope that helps