No argument from me about having the helper. If you don't have a helper:I'll add to @JFHughes8088 comment on DIY. It's a MUCH easier job if 2 people are doing it. There's alot of placing and manipulating of the rack position on installation and it helps a lot to have someone in the car and someone in the wheel well while doing it.
Before removing the existing rack, I cut two 14-18" pieces of 3/4 ply that I had laying around so that I could insert them under the old rack, then a piece to fit behind the rack in the box section holding the rack. That held the rack upright so the bolts could be put in. At that point, the rack was supported in two axis. It turned out that that small forethought made installing the replacement rack easier. I also loosened the fixings under the dash so the that column was loose. I didn't need to do that to remove the rack, but I had to do that to get the column connected to the rack on reassembly.