replacing rear springs, lots of questions

I have to change the rear springs on my 06 4X4 double cab, can anyone tell me if they're any little tricks that would help me? it looks like just unbolt it all and slide the old one out, then just slide the new one in. my biggest question is are there any shims or anything that align the rearend with the rest of the drivetrain that I have to worry about? it doesnt look like it but I dont want to tear it apart and then get surprised. any advise would be greatly appreciated.
thanks

 

Get new ubolts and ask a friend to lend a hand. Good luck!

 

There are center pins that go through the leafs that align them, if you can, use new U-bolts, this will help too if you can't get the old ones off without cutting them. and soak all the bolts for a couple of days prior with PB Blaster.