Wow I don't feel so bad for being confused. There are two totally different convoluted approaches to this (.ins file versus .map file) that even the CW community is divided over. So, I went with the .map file approach, and this was my experience:
1) xcopy installed the map file that Subjacent wrote to my X3 program folder (didn't get the location right on the first try)
2) Restarted X3
3) Had to convert my instrument track to separate midi/audio tracks and redirect midi out (don't think this can work any other way!)
4) Drum pane works now and has the drum names and shows my MIDI notes. Oddly, the piano view is still visible under it but the notes are gone...I wonder why that is??
5) I experimented with Subjacent's template file, but that throws a missing "Console Emulator Bus" plug-in error. I don't need to go there.
Pretty baffling, but I got it to work. I'm a software engineer with previous Sonar experience, but I think a lot of newbs will be roadkill when they encounter this. Really this basic drum editing is the first thing a lot of people are going to attempt, and are quickly going to find themselves off in the "hacker domain" just to get a basic environment set up.