Hydraulic clutch line.

1996 gmc sonoma sl 205 kilometers 2.2 motor 5 speed trans. 2 wheel drive. I am replacing the clutch assembly. How do you release the line from the inside of bell housing? My Haynes book said to push the white plastic down with 2 small screw drivers and pull out the connector. I pushed the white plastic collar down and it still won't release. It is down level with the brass body. Does it have to go further inside to release? My 92 Ford Ranger had a similar set up, but it popped off easily when I pushed the plastic down.