How would you clean a litter robot?

I have a litter robot 4. I’ve had it for about a year and never cleaned it inside the main litter box. (I was pregnant and postpartum so that’s my excuse.) it’s pretty bad and I need to do something. I live in a one bed condo with no room and no outside access to a hose or anything. How would you go about cleaning it?

The only idea I’ve had is maybe washing it in the tub but I’d like to avoid it. Baby bathes in there and it’s nasty.

I also thought about maybe taking it apart, putting it in the car and going to a car wash or something. Idk help!!