Spring removal and Columbia installation

[SoCalCoupe]

Borrowed a spring spreader and got started.


Took a last drive and topped off the tank with fresh gas.


Jacked up the driver's side of the car and removed the rear wheel and hub. Removed the four bolts from the backing plan and quit for the day when I realized I'll have to disconnect the brake line. Didn't want to get into that but there's no choice. Trying to figure out how to seal up the brake line and wheel cylinder when I disconnect them. Any thoughts?
Don't know what kind of brake fluid is in the car. Any thoughts on to identify it? What should I put back in?