I have the same unit and replaced the pump a few months ago. I took the pictures below as I did it.
First, unplug the unit and remove the water tank. Now go to the back and remove the six screws:
Now slide the side panels toward the back of the unit until you can pull them away from the sides:
Here's the view from the back:
The pump is on the right with the green and white label on the side. It looks like this:
Now disconnect the 3 hoses going to the pump and the 2 wires. Again, the unit needs to be unplugged as the pump uses 120VAC.
The hoses are attached in three different ways on mine. One has a simple clamp you remove with pliers, one uses a cotter-pin that you pull out with pliers, and the bottom hose is just a friction fit. It is pretty obvious but of course keep track of what goes where.
The wires might require a bit of pulling so be careful.
The only thing tricky I can recall is that the top fitting of the pump (where the top 2 hoses are attached) is screwed on to the pump so after the hoses are removed you can gently unscrew it from the pump.