Puritan Bennett 318 Plus CPAP needs adjustment

Does anyone have the instructions for setting the pressure on a 318 Plus.
I have it as a spare unit and wanted the pressure adjusted but the local
service center doesn't want to be bothered by trying to find the instruction. They just tell me to buy a new machine.....its set at 10 now but needs to be set at 9. I have the cable to connect to the serial port but cant find the setting to connect to the unit.

gregf69@hotmail.com

I have a pb 318. It is an earlier model that I bought on e-bay as a backup. is a bit noisy but nice.

There are two small holes on the bottom that you insert a nail or something similar that increasea/decreases the pressure.

The main think I used mine for was when my computer fan broke and I was waiting for a new one. I turned it on and clipped it to blow on the cpu.
worked like a charm.
CPAP can be versatile.