First, I had to replace a cracked roller so I could roll the frig out. I did this by tilting it slightly and shoving a shim underneath. I had to use two shims to get enough clearance for the wheel. I unscrewed the old wheel, screwed in the new one pretty easy, removed the shims and rolled it out.
Then I unplugged the frig from the power socket, removed 6 screws from the back panel, and pulled out the old drain kit, which had become clogged with dirt and dust. I put in the new drain kit, replaced the back panel, plugged it in and rolled it back, good as new.