You are given this by Crazy Earl and is just in the middle for how hard it is.
Earl's Best Friend Freed 0/1
Just run the the way point and kill enemies on the way when you get there take out the bandits before setting him free.
Also before setting Scrappy free there is a red chest outside his caged area open grab stuff if you need to.
Then set Scrappy free and turn in to Earl.
Scrappy after you kill "The Destroyer" you will find in Earl's Scrapyard and Scrappy will be called Scrappy,All Grown up. You can engage battle with him and kill him.