[Notanlines]

Your best bet is to watch about three different vid's on youtube and combine the knowledge of all three.
I usually start by hooking up the compressor to the exterior service for water supply, set the pressure at 30-40 psi and blow the water out of all lines, open all low point drains, drain the water heater, turn the by-pass valve on the rear of the water heater, remove the rod on the bottom of the water heater, and then pump pink stuff through all lines until it flows bright pink using the RV water pump. I leave a little in all the drains, always remember to include the commode, black/grey tank flushes and exterior rinse hoses. We never put anti-freeze in the fresh water tank nor in the black or grey tanks. We just insure that they are all empty and remain open.
Others will chime in on this with varying methods used with success. Keep in mind that there is no such thing as too much anti-freeze in your lines, only too little anti-freeze.
Take your time, do it yourself, no outside help from eager helpers. This is a very important step in RV maintenance.