To peplace the rear brake pads, do I need to remove the rear wheel to get at the pads?
Is there a way to do this without taking off the rear wheel?

 

You do not need to remove the wheel.

1.) Take off mastercylinder cap
2.) Use putty knife, screwdriver or what ever to push pistons in. Don't worry about gouging old pads, they are getting trashed anyway.
3.) Use 1/4" 12pt socket to take out pad pins. Pads will fall out.
4.) Put new pads in and torque pins to correct specs. (even though, I just tightent to "just right" and use no torque wrench)
5.) Put master cylinder cap back on and pump up brakes.

It takes me about 10 minutes to change a set of pads.