No need to blow out water in lines prior to adding antifresh.
I would drain the fresh water tank, bypass and drain the water Heater. also remove water filter if so equipped. (I connect the inlet and outet water filter hoses together with a short length of 1/2" nipple so that i don't introduce antidfreeze into the filter housing.)
Then use the demand pump to purge water in the lines with pink stuff. After all lines (and traps) are filled with anti-freeze, remove the filter screen from the city water fill port and depress the check valve to allow antifreeze to flow back through the city water fill port.
Cathy & Jeff
2013 Sabre 32RCTS / 2012 Ram2500 Hemi
Nights Camped: 2015-140; 2016-137 YTD; 160 Planned