Kapro 1500mm Anodized Screed Level
First you need to find where the timber studs are in the wall. Use a stud finder and mark the left and right side of the stud. Run a plumb line down the centre. Remember you won't be able to see these lines once the cabinet is in place. Make sure you measure out from the corner and note the distance to the centre of the stud.
Move your cabinet into place. Use your spirit level and adjust the feet until it is level and plumb. Transfer the stud measurements to the front of the cabinet. Mark a line up the back of the cabinet in line with the stud position. Pre-drill through the back rails at the top and bottom of the cabinet. Screw the cabinet into place. Then position the shelves inside the cabinet and adjust the door.