Roll under and pull the "pin" (has a cotter key in it) then attempt to swing it out and in.. If that is difficult then lube all the joints..
With the pin removed you can check the wiring for corrosion and damage without fear of chopping your arm off if it activates.>>>Dan
This might not be your problem but the electric motor may have worn brushes which have quit working in one direction. Nearby RV repair places wanted to sell us a new set of steps instead of just replacing the motor. On mine I found it was a slightly older Ford electric window motor. I had to identify it by finding a site with dozens of pictures of various motors. Then Googled to find the best price which was less than $50 with shipping. As Utclmjmpr said once you remove the pin connecting the motor to the steps they should slide out easy. Then the motor is pretty easy to install if you work under the RV instead of taking the steps off. Since I like to play with things I found the motor brushes on another site for $7 and fixed the original motor so I now have a spare. A friend had problems with the magnetic automatic open/close sensor in the door and door jamb and replaced all that with a dual pole toggle switch next to the on/off switch just beside the door using its hot wire. $5 fix from Radio Shack.