You definitely want to do it through the fresh water inlet, using one of
these adapters. I start by opening the kitchen faucet and then turning on the compressor. Once both hot and cold blow just air I open a bathroom faucet and shut off the kitchen. Once the bathroom sink is done I do the toilet and then the shower.When those are done I open the outside shower and then shut off the main shower. Once all faucets are done I open the water heater drain and then a low point drain. When those are clear I leave them open and shut off the compressor.
I like to drain the holding tanks one last time if possible before I pour AF in, but if I don't have time I don't worry about it much. Make sure to remove the filter cup on the water pump too. This is how I do mine, others here have different methods and opinions.