Open the cabinet in which you wish to install your new pull-out shelf. Empty the contents out of the cabinet, leaving nothing inside.
Open the packaging containing the new pull-out drawer and empty the contents. The packaging should contain one pull-out drawer with rollers already attached to either side or underneath, along with two slide rails and mounting screws.
Put the two slide rails into the kitchen or bathroom cabinet and mark the location of the mounting holes in the cleats on the rails with a fine point marker. You will mark between eight and sixteen holes in the four cleats total.
Pull the slide rails out of the cabinet, then drill pilot holes into the marked locations using a drill and an appropriately sized bit.
Fit the slide rails back into the cabinet, aligning the mounting holes in the cleats with the drilled pilot holes. Insert the mounting screws through the cleats and into the pilot holes. Fasten the screws in place with a screw gun.
Place the pull-out shelf onto the slide rails, putting the rollers into the mounted rails to complete the installation of your new pull-out shelf.