When doing the back shock, it is a lot easier if you remove the plastic panel under the deck and loosen the bolts holding the plastic panel that the shock goes through. Then you can reach right in and put that upper bolt in without much work at all. It takes a little more time to do, but sounds like you have plenty of time up there right now with the weather. As for the spacers, you want the wider ones on the bottom and the narrow ones up top.
This is what I did - - very easy this way