It took about an hour to finish and I'm expecting some lower power
bills this summer compared to last summer since one side of the
condenser had the coils totally clogged with dirt and dust.
Here's the guide - http://www.paulstravelpictures.com/Rheem-Classic-HVAC-Condenser-Coils-Cleaning-Guide
Be sure to turn off the power to the A/C system at the breaker box
inside the house and also at the breaker box outside near the
condenser before you get started.
Cheers,
Paul