How to make a pull-out drying drawer
Take the back and bottom panels, and hold the ends flush together. You can tell, which one is the bottom by the feet imprints on its face. Drill and screw the ends together in the guide holes until they are tight and square. Guide the screws in slowly to avoid any splitting of the material.
Each side panel has two little holes in the corners for the rail support. These should be at the front of your cabinet. Take your two side panels and screw them to either side of the cabinet gently. If the panels are not flush, loosen the screws a bit and give the panels a tap with your mallet to square them up. The side panel will protrude past the back panel about 20mm. This is designed to help you with installing the cabinet if the corners of your walls aren't perfectly square.
Lay the cabinet on its base. Take one end of the rail support and line it up with the two holes on the front sides of the cabinet. Twist in the screws a short way by hand, to hold the rail in place, while you screw in the other end. Now tighten the screws with your power drill. Once they are in place, give the rails a tap with your mallet to make sure that they are square.
Once you have assembled all the panels, turn the cabinet upside down and attach the adjustable feet. Connect the top part of the feet to your base panel first, using the four imprints as your guide. Make sure the angled sides face the edges of the panels. Be gentle when screwing them in to avoid cracking the plastic. Then insert the feet stems and finally the bases. Manually twist the bases of the feet to adjust their height, and use your compound square to make sure they're all the same length.
It's a good idea to insert the shelf before you install the cabinet under your benchtop. Turn the cabinet over onto its feet. Take the peg brackets and insert them into the shelf holes inside the cabinet to support the shelf. There are five pegs, two for each side and one for the back. Finally, insert the shelf onto the shelf pegs, and you are done.