Being new I might be wrong but here is what I believe about stagger. To add a small amount of stagger, like a quick adjustment at the track you can add air to the RR and reduce air to the LR. The problem with this I have found is you might get too much air in the LR. For a quick adjustment you can add a half a pound to RR and remove a half of a pound from the LR.
At first I needed a larger amount of stagger adjustment than I could gain with air pressure. I had to stretch the LR about a half an inch. I inflated the tire to about a half inch over what I wanted it to be. I wrapped my tape measure around the tire and added air until I got to where I wanted it to be, then set the tire in the sun for a couple of days. When I let the air out the tire was where I wanted it to be.
I got the RR to shrink a little bit by doing the opposite. I deflated it and set it in the sun deflated. When it got good and hot, I dunked it in ice water.