Hi, thanks for using JustAnswer.com. There may be an adjustment screw on each side near the bottom hinge of each door. You will have to remove the kickplate and lower hinge covers to see the rear adjustment screws. The front screws are the only ones exposed with the hinge covers on. Remove the hinge covers and you should see the screws.
The rear wheels are not adjustable. You will need to use wood shims to level them. Number 30 in the picture is the rear roller. They are secured in place and are not adjustable.