How Do I Do It??

Copy the midi data from one to the other.

Cheers,
J

open AD drums 2 then drag your midi file (from SI drums) on to the AD 2 track.
open up the Piano roll view and look for possible mis matched notes.
sometimes the drum maps are different and instruments will be in different places.

I use midi tracks, not the simple instrument track. 
So all you do is point the midi drum tracks output at AD2.. But .... AD uses a different drum map. so you now either open AD2 and change it's drum map to GM or better yet, open piano view and in turn, highlight the note using the piano keys, then using the move tool with snap on, drag note to the correct new location. 
Example GM hi hats will show as a rim shot in AD, so drag them up to what ever one of the AD hi hat note you like best,,, there's about 6 different sound. 
The open hi hat in GM becomes a crash. Anyhow you get good at it and for me it's pretty fast. 
I might leave GM drum tracks that contain a lot of percussion sounds in the TTS_1 and only move the main kit parts over to AD,, cut / paste,, or drag and drop both work fine but keep that snap setting on so things stay put in time. 

So, that is easier than changing each row's midi note number or some other way? I've been wondering how to do it the simplest, most efficient way. I'd like to use Step Sequencer when I arrange the drum track, but want to play the fills on midi pads. So, I'm wanting to combine them with AD2 sounds.