Put on rubber gloves and pour acetone into a spray bottle.
Spray the underside of the desk in a corner where the laminate overlaps and let soak for about 30 seconds.
Slip the blade of a paint scraper between the laminate and the wood, then gently begin to separate the laminate from the wood in the corner. Spray more acetone, if necessary.
Pull the laminate away from the corner slightly, then insert a putty knife under the laminate and spray more acetone between the underside of the laminate and the desk.
Scrape up the laminate with the putty knife slowly from one side of the desk to the other until the laminate is completely removed from the desk.
Measure the width and length of the desk's top with a tape measure. Then measure and mark cut lines on the underside of a new piece of laminate with a pencil.
Score along the pencil-drawn cut line repeatedly with a utility knife, then snap off the excess piece of laminate.
Spread contact cement over the top of the desk with a paintbrush and let stand until tacky but not dry.
Place dowels over the top of the desk every 8 to 10 inches, then sit the new laminate on top of the dowels.
Remove the first dowel from one end, then press the laminate flat against the desk with a hand roller. Remove the next dowel and press the laminate again with the hand roller. Continue to take out the dowels and press the laminate until the top of the desk is covered, then fold the edges up under the overlap around the edges of the desk to finish.