This may be fairly basic but I can't find any info on how to do this.  I cannot automate or mix separate Session Drummer tracks, as in if I change the volume on one track it's changed on all Session Drummer tracks.  Any solutions?

Welcome to the forum.
Use seperate instances of SD using different channels for each one.

Easy to do. Assuming you are not using a simple instrument track, but have that split as a midi track and an audio output track.

Open the Session Drummer mixer. At the bottom under each piece is a number. Think of those numbers in terms of 2 4 6 8. They probably all say 1 at the moment for you. Say you keep the kick at 1, but change the snare to 2. All the tom pieces to 3. the crash to 4 etc.

Clone your audio track to how many pieces you want to mix separately. Name those audio tracks ( kick, snare etc).

Set the input of those audio tracks from Session drummer with different input numbered 1-2 being kick, 3-4 being snare from the above example. Essentially multiply by 2 what the number is in the Session Drummer mixer number you've selected. thus Snare is 3-4, even though in Session Drummer's mixer it is 2.

Thanks, both seem to work for this or that.  I found creating a new track and copying the clip instead of cloning the track seemed to work.  Cloning then changing the channel seemed to do nothing?

I'll describe it another way. (You can save this as a track template and you'll be off to the races the next time).

Insert a new Session Drummer instance. Choose all separate audio outputs. You'll get one midi track plus separate audio tracks for each piece automatically.

Paste your one midi clip onto the one midi track on this new instance.

Open up the Session Drummer mixer on the new instance (everything is on this new instance from here).

Under the kick drum leave it at 1. Under the snare change it to 2. The toms pick 3 for all of them. The hi hat pick 4. Crash 5. Ride 6.

The above is all on the mixer of the midi track of Session Drummer.

Now go to each of the audio tracks under this instance of Session Drummer.

Think times 2.

Kick is input on audio of Stereo 1-2
Snare is input Stereo 3-4
Toms are input 5-6
Hi hat is 7-8 etc.

When you play back the midi after setting the above pattern from one midi track you'll have separate audio per kit piece. Great for the Console View for mixing, and great for freezing Session Drummer and continuing on with the freedom to mix.

What I referred to in my previous post is that if you have a simple instrument track you can split it into a midi and matching audio track. From there you can clone the audio track a few times and then assign the audio inputs as above to get the same result.