NefMoto

I got intrigued by map switching. Is there any place with clear info on this, as I'm finding it hard to understand  a few things;

I know there is a lot of free space within my bin, so i suppose the maps I'd like to swap should go here, and the different iterations of it. But how do i make the calls to switch them? I just got the hang of hex editing and I'd like to know how its done or where to find some good info rather than copying some stuff over and trying untill it works.