The advice to hold the plane off the ground is the best advice here. Get close to the ground, keep it straight down the runway, slowly pull the power right off, and then pretend that you have decided not to land after all, and hold it off (don't add power of course). Even after the wheels touch, keep holding it off, it really helps with slowing down.
Don't worry about running off the end of the runway. If you crossed the threshold at the right speed and altitude, then land as we have suggested, you'll be fine. The plane will slow down as quickly in the air, as it would have on the ground anyway. You're not using any brakes until the very end of the roll out anyway.
Relax, you'll do fine...
Pilot DAR