I was able to do it with the rear wheel on but there was some trick to it, I think I unloaded or compressed the rear suspension or used a stand or leaned it up on the kickstand or something to help pull the wheel back a little more. I THINK if you compress the suspension, it moved the rear tire back slightly and was enough for me to wedge it out. I can't exactly remember but I'm 100 % sure I did it without removing the rear tire because I didn't have a socket to loosen the rear axle yet and I did the exhaust myself.
Like mentioned above, you can loosen the rear axle, push the tire a little forward to remove the chain and then pull the tire all the way back to give you the clearance needed without actually removing the rear tire. Not a lot of people have a socket to do this though.
You can easily remove it without taking the tire off, or without loosening the axle nut. Just wiggle it a bit. I had removed it from one bike which was on the stands and second that was simply on the kickstand. Also have a look at this guys video it should help
Don't need to touch the axle, chain, or suspension on the 13 to remove the pre chamber. Deflate the rear wheel and turn the wheel as you remove the chamber. I ruined my gasket when I did mine because I rushed but the new one was cheap and I needed it for the Pinebox.
I removed mine with hand tools. It was on it's kick stand. Air was 42psi rear and 36psi front. I removed the muffler first. Then on to the pre-muffler. I just moved it and wiggled it until it came off. I had zero issues. Installed a pinebox design link pipe in its place and replaced the muffler with a Yosh. RS-4. Sounds sick!!