Hi, congrats on the new amp... i had a purple stripe MKIII that i had the R2 mod done to by Mike B at Mesa many moons ago, so I can't give you any info on how to do it, but I can say that after I had it done, i kinda regretted doing it. The "crunch" channel lost its "mojo", so instead of sounding fat and thick, with that "on the verge of breakup bloom" it sounded thin and kinda lifeless. I could balance the three channels volume after the mod, but i honestly would have reverted back to stock if i still had the amp. i had to sell during the recently ended "depression"... i was also living overseas at the time, so i just brought the chassis with me when i visited family in california and sent it to MB for the work, so when i was able to test was when i was back in europe and slapped it back into the combo and fired it up, that was the main reason i couldn't have Mike B adjust the mod or undo it, you might wanna try contacting MB.... sorry for the long post, hope this helps a bit...and as always, ymmv... good luck....
peace