Select and Place
Pool table slates come in many different types. Talk to an experienced professional about the price and quality point of each before making your decision. Once you've carted your new purchase to your house, enlist a friend or two to help you carry it and place it (it will be extremely heavy). Place the slate gently onto the exposed pool table slate supports, making certain that it does not get bumped or chipped. Measure the slate in reference to the pool table itself, and check to see that it is centered exactly. If you are using a three-piece slate, start with the center one and add the ones at the edges after measuring.
Leveling
In order to work properly, your pool table will need to be perfectly leveled; however, unevenness in the slate supports will probably leave the newly positioned slate a bit off kilter. Placing a level on the slate, drive wooden wedges in between it and the frame of your pool table. Do so carefully and consistently, taking as much time and care on this step -- hours if necessary -- as you need to. Check the level from every possible position on the pool table once you think it is close to perfect.
Finish the Job
Now you're ready to make your pool table slate permanent. Use slate screws to screw the slate into place at the outer edges. Check your level after each screw is installed to ensure that it has not changed, and adjust as needed. Fill any seams or openings with auto body filler or wax. Check the slate for chips and indentations that might need to be filled in. All of the other appointments, from laying felt to adding decorative siding and pockets, will seem easy after you've tackled this project.