Modern version, since this always shows up first in my search results when I forget how to do this xd Use TesVEdit or SSEedit and open up the ones you need, you can go to file header on the esp files you want to be masters, right click in the field to the right of Record Flags, click edit, then select esm. (may be optional, depends on whether CK is acting up or not) You can then add those esps by going to the file header of your esp that you want to work on, and then right click next to Master Files and hit add Right click on the new master that appears and type in the name of the esp you want to add as a master, this is case sensitive.
