Removing the cylinder and crane does not require gunsmithing skills and it could just be a matter of cleaning and lubrication.
However, as with everything, there's a little trick involved: After removing the set screw, open the cylinder and lay the gun on its right side. Holding the cylinder in place, pull off the crane from both the cylinder and frame. Re-assemble by holding the cylinder in place, then inserting the crane through the cylinder and frame simultaneously.