Regarding application, contact cement is the right adhesive for the job. However, you'll need to spend some time removing all of the original adhesive. In the past when I've done the job, I used a single edge razorblade at an angle a bit off perpendicular to scrape off the old adhesive, and it works quite well leveling any non skid material too. Prior to application of the contact cement, carefully sand the deck to create a optimal bonding surface.
Be sure to apply the contact cement to the bottom of the pads and the surface of the board to cover the entire area where the pads will go. To get the best result, be careful to avoid getting any contact cement on the board outside of the area where the pads will go. I've had the best luck with achieving a good bond by applying two coats of contact cement to both the pads and board. Be sure to allow the contact cement to dry before applying the pads to the board.