[1999R4]

There really isn't a need to take them out if you are just cleaning the sump; I clean mine once a year and have never removed the stairs.  I can reach the front two screws on the sump cover and can also remove and replace the tube filter inside the sump once open (with screwdriver).  The back two screws for the cover can be removed and replaced using a screw driver that allows the tip to angle (20-30 degrees or so) and a grabber. 

   

   

To remove simply unscrew completely and ten use your grabber to get the screw out.  To replace, use the grabber to set screws back in and push down slightly to center it and bring it to vertical, then angle your screw driver to tighten it down.

Once open and you have removed the tube filter, spray some Clorox Clean-up, let sit for a few minutes and then use a toilet brush to agitate and repeat as necessary.  Either use shop vac to add water and use your screw driver to lift the float to discharge cleaning solution.  Keep repeating until all mold and gunk is gone.

While it isn't very comfortable reaching through the open stairs, it isn't so difficult that taking out the stairs makes the overall job easier.