Need to replace washer hook up valves

[igapo]

Its been a long time since I've cut into pipes. My hot water has a secondary shut off before the gate valve to the washer so that one should be easy to replace with a push fitting ball vlave. My main water needs to need to be shut off to cut and replace the cold water valve. After shutting off main, do I need to drain the entire house, or most of it, before putting on a push fitting valve or can it be put on while water is coming out? In my head, this should be very easy, Thank you.

 

[frodo]

depends on if you want to get wet or not..