Get the viper or tubb barrel vise from midway or brownells (same exact vise just different name and finish), buy my action wrench for $125 shipped, get a 1/2" breaker bar (you shouldn't break the barrel loose with a torque wrench), and get a QUALITY torque wrench that goes to at least 100ftlbs, preferably that 100ftlbs isn't the max or minimum as it will be more accurate in the middle of the range. I recommend snap on, if you must skimp then at least by a craftsman, don't buy the shit from harbor frieght.
You clamp or bolt the barrel vise to a sold surface, wrap some paper around the barrel so it doesn't marr the finish and tighten the bolts on the vise hella tight. Insert action wrench with breaker bar and crack it loose. Only crack it lose, remove the gun from the vise and unscrew the barrel with the gun in a upright position, this will keep from damaging the tennon and action threads. Make sure action face and barrel shoulder of new barrel is free of debris (wipe it down) use some light oil on the threads and spin the new barrel in. Put it back in the vise, insert action wrench and torque to 100ft lbs.
Taking your time and removing the handguard to clean the receiver face this should take no more than 15 mins. You can get in the slots with qtips though to swab the face, if you do that and take your time 5-10 mins. Very easy to do.