64 Barracuda slow going.

Ok , I dont have any pictures yet but Im excited because ive got some parts comming soon to solve my airshocks issue.
I ordered some new rear shocks 2" longer than factory and will order new 3" lift rear leaf springs tonight. So I should be able to clear my rear tires easily now and get a better ride without the risk of a blown airline ruining my rear tires again.
My question is this, do any of you have any advice/ tips for when I go to install the rear leafs? No lift, just jack stands and jacks.
How long am I looking at time wise? And yes I will have new u bolts before I start.
Thanks for any advice.
Oh and I also ordered a new headliner and padding to attempt myself even though everyone says not to, I figured I can always pay to have it done professionally some day when I can afford it later.