Yup piece of cake. Seat off, cover that area with a towel or blanket (tank too) remove TP and place on covered area (I found I had to do this due to the speaker wires). Old rack off, new rack on (be sure to read that part a couple of times. I almost messed up.), TP back on, seat back on and done.

2 hours sounds about right. It makes a big difference for you and your rider.