Vinyl laminate on a door is meant to provide durability, but that doesn't mean it will last forever. If that layer of vinyl has become tatty and damaged, you can laminate over it or replace it to give the whole cabinet unit a new look. If the vinyl is partly missing or loose, it should come off; but if it's still firmly fixed to the door, you can laminate on top of it. See your home improvement shop for the right kind of laminate and related materials for your project.
Remove the doors from the cabinet frame using your screwdriver. Lay them out on a work space.
Sand the vinyl surface of the first door with your pad sander, getting it smooth, flat and dull. If there are any loose or missing parts to the vinyl surface, pull the whole vinyl layer off and work with the bare base instead.
Measure the dimensions of the door front. Add an extra 2.5 cm (1 inch) all around, and mark out those dimensions on a sheet of laminate with your pencil and carpenter's square.
Use your razor knife to cut the piece along the lines.
Peel away the paper from the back of the piece. Press it to the door's surface, overhanging by 2.5 cm (1 inch) on all sides.
Wrap the wood block in a towel and press it across the surface of the veneer, from one end to the other, to stick it to the surface firmly and to squeeze out any air bubbles.
Use your razor knife to cut away the overhanging veneer from the perimeter of the door, running the blade at a 45-degree angle along the edges.
Repeat for each door. Reassemble the cabinet.