I actually had to do that this spring. Mine was leaning in, not out. Basically we took out all the blocks, leveled the base (make sure to use sand and get it really level), and laid the first row (usually you want three bottom row to be 1/3-1/2 of each block to be underground). Then offset the second layer. Repeat. Make sure to backfill into the cracks as much as possible (sand almost works better to fit into the spaces between cracks as it acts like a barrier to keep dirt from turning into mud and washing out in a heavy rain). If you need pictures, I can try and go get a few to show what I mean.
