First, remove the old cabinet doors and drawers. If the wall is finished, use a stud finder to locate the studs and mark them with a pencil. If the wall is unfinished, use a level to mark the placement of the top edge of the cabinet.Drill holes in the wall at each marked location, then insert screws (or nails) into each hole. Hang the cabinet on these screws or nails, making sure that it's level. Finally, attach the cabinet doors and drawers using either hinges or drawer slides.

1. Decide on the placement of your cabinets. Premade cabinets typically come in modular sizes, so you'll need to measure the area where you want to install them and make sure you have enough clearance on all sides.2. Mark the wall where each cabinet will go with a pencil.3. Remove the cabinet doors and drawers and set them aside.4. Install cabinet backing, using screws or nails, at each mark you made on the wall in step 2 (this is typically done by a professional). Make sure it's level before moving on to the next step.5. Place the cabinet carcasses one at a time against the backings.