Just do it like beer.
Or, if that's not detailed enough:
Clean and sanitize your kegs, purge and pressurize. Use a filler head or remove the backflows from a regular tavern head and bee careful (buzbuz). Attach brite tank liquid out to keg liquid out and slowly open the gas-in on the keg side.
Stick the thing on a scale before you start so you know when you're getting close.