Measure the height of your dresser and the thickness of the board you will use for your desktop. Attach short pedestal feet to the dresser using screws, if necessary, so that together with the desktop, the dresser reaches the desired height for your work surface.
Attach the tall pedestal feet to the other side of your desktop using screws. Use a level to ensure that the tall feet are the same height as the combined height of the short feet and the dresser, itself. Add shims between the bottom of the desktop and the tall pedestal feet, as necessary.
Sand or saw off any elements of the dresser that protrude from its top surface. Screw the desktop to the top of the dresser. Use sufficiently short screws so that they do not show through the desktop.
Decide which side of the dresser you will preserve as drawers and which side you will hollow out into a desk. Remove all the drawers from the dresser. Use a jigsaw to cut the framing elements out of the side where you will sit. Do not cut any framing elements necessary to support the other side, which will serve as drawers.
Identify which drawers are in the best shape and check that they slide easily into the drawer slots you have retained. Sand, stain, repaint or replace their hardware, as necessary, to complement the look of your new desk. Wait the full length of time indicated by the manufacturer to allow all stains or paints to dry completely. Do the same for the dresser structure, with complementary or matching colors and finishes.
Sand and saw down any elements that protrude upward from the top of the dresser. Attach a laminate or wood board to the top of the dresser, to serve as your desktop. Allow an overhang on one or both sides, accounting for the space in your room and your personal aesthetics. Finish the desktop with stain or paint, as necessary, to coordinate with the base of the desk. Follow the manufacturer's instructions for drying time before using your new desk.