Petcocks are threaded right into the fiberglass and sealed with 5 minute epoxy. This sealing works well. To remove, simply put a big crescent wrench to them and loosen. It may sound like you are tearing the tank apart but you are not. To re-install, reapply 5 minute epoxy all around the petcock threads and tighten. (Don't get any in the fuel passage hole.) Do not wipe away the little bead of epoxy that appears. Give it a couple of hours to cure even though it says 5 minutes. (KR tank has ¾" petcock female threads permanently glassed into body for Harley/Pingle type petcocks.)
Anti-ethanol. As of the beginning of 2017 we now use a new gray coating. The old "Blue" tank coating couldn’t handle California fuel. It was fine for the rest of the nation but we made the change anyway. We did a long term soaking test with gray stuff on a fiberglass sample and the stuff worked perfectly. We thank Robi Mori from San Francisco for prompting this change. [Side bar: Rob said he only got 16 miles from my tank. I was stunned and wrote back saying he should be getting well over a 100. He replied that he has a monster motor and a bucket for a carb. Rob can’t get out of the city without refilling. I’m sure he’s a terror in that Wester town.]
A word about pump gas. Even though my tanks are designed to withstand ethanol I am still gun shy. Let me share with you what I do. Here in Minnesota there are a few stations that still have a few pumps with premium non-ethanol for vintage cars and recreational use. That's what I use. I have learned the ratio of alcohol in pump gas can vary between 4% and 12%. That high end worriers me. Pumps showing E-85 scare me even more. If you have a choice use E-10, not E-15--better yet premium non-ethanol.
Ethanol is junk gas. If you let your bike sit unused for a month or more chances are your carbs will be full of green slime. A total carb cleaning is the only cure. To avoid this 1) drain your float bowls prior to a period of non-use. Option 2) while bike is running at idle, turn the petcock(s) off and let the bike drink up all the gas in the carbs. Either of these two options will be the cost-avoidance solution for using junk fuel.