Slim's method works great Krystal. He sent me some pics couple years ago and I did the same. Just replaced all my barrels again with same setup. Only mods I made was I cut smaller openings(doors) and left a bigger lip on bottom of doors to hold the bedding in. No complaints here
I just used small chain and eye hooks with a fender washer. Holds all the dogs fine, even my big ole meat headed dogs.... I know its hard to see but here is my set up.