Need some help Power leveling

Hey I’ve just started playing again (after about 2 years) and I was wondering if anyone could help me power level my friend from 65 to 72 as I really can’t remember how I use to do it so fast

If able please message me on xbox 360 my gt I a thaatus DOX

if u and your friend got mister torgues campaign of carnage dlc just do the bar room brawl over and over and get him xp that way