get ready for a lot of cussing, scraped arms, banged knuckles, and pinched fingers....it can be done by yourself, but best to have an extra set of hands.....I have used cable ties to pull them together.....
it can be a bit of a challenge.....and especially since you have a stacked set, you may have to take the dryer off to reach over the top.....
also sometimes helps to take the front cover off of the tub and lay it on the floor to get that boot and spring back on.....then reassemble....
this guy makes it look easy, but that spring is TOUGH....
let us know how you make out.....