If you want to make further changes you are going to have to have a look at the files and work through them.
Ive explained what the new extension does.
Look at the file structure, the names of files, where they are linked...
Ultimately - depending on what you actually want to change - you need to understand that your table right now does this:
Loads CoreRPG - Loads MoreCore (which overwrites a few CoreRPG things and then adds a bunch more) - Loads MCSotDL extension (which overwrites a few CoreRPG/MoreCore things and then adds a couple more) - Loads MCTest extension (which overwrites a few MCSotDL and MoreCore things).
If this is new to you - dont expect to understand it straight away.
Unpack the two extensions and MoreCore and make a few small edits and reload FG and see what happens.
Ultimately you should not make changes in CoreRPG or MoreCore you should only change extensions otherwise your work will get overwritten when you load a new version.
Adding in more stuff is fine. You just need to make room for it.
There are plenty of examples between the extension, MoreCore and CoreRPG.

