It's best to bench to bleed it as much as possible (immerse the inlet in fluid and pump the rod until all the air is out). Then when you're sure it's full and all the air is out get under there and have someone hold the pedal down or brace it to the floor with a piece of wood and pull the seat all the way forward to hold it. Get under there and hook up the line and position it in the bell housing (don't pop the plastic strap!).
Once it's in there release the pedal and suck as much air up the line as possible.
Then wait a little while for the air to rise up to the clutch master. Make sure you're done with everything and it's in tight and pump the pedal a couple times.