ResMed Sullivan BIPAP Pressure Settings

I have an older model ResMed Sullivan Comfort bi-level that I used originally years ago when first diagnosed with sleep apnea and now use it only as a back-up unit to my new Respironics M Series BIPAP Auto. Due to a recent sleep study it has been determined that I would need to lower my IPAP & EPAP pressure settings from 16/12 to 10/6 if it became necessary to use my Sullivan Comfort bi-level unit. I am looking for a copy of the Clinician's Manual for the ResMed Sullivan Comfort bi-level or at least the instructions for adjusting the pressure settings. Would appreciate any help/assistance that might be available. Thank you!

Have you ever found anything out on adjusting the pressure settings. My husband has an older model as well. The back pressure somehow either got turned way down or off. Do you have any information on changing that? We were successful in changing the initial pressure but not the backpressure. We don't have insurance at the moment so any help would be awesome. Thank you.