I have always been frustrated trying to remove those rock-hard fuel return lines that are on the injectors. You can tug on them, and often they break. You can try to carefully use a blade, but then you risk nicking the barb and will have leaks.

Tonight I used a heat gun (got mine from Harbor Freight for $9.99) to heat the hose at the nipple. I put the nozzle of the gun just 2-3 inches away from the nipple area, and just applied heat for about 5-10 seconds on the high setting. Without waiting more than a few sconds, I grabbed my needle noze pliers, grabbed the hose just above the nipple, and they would pop right off. I tried one without heat and couldn't get it off, applied the heat, and it immediately came off with very little force. I had all hoses off in about 3-4 minutes, versus the one time I spent 20 minutes on one hose!!

Please be careful, as I suppose it is possible to apply too much heat and ruin something or start a fire! Just enough to heat the rubber and cause it to soften a bit. You might have the same effect if you just tried to remove them right after driving the car, but then you have the issue of working on a hot engine, which has its own hazards.

Maybe this will help someone and curious if others out there already used this method.