[Tx Firefighter]

Open the bleeder or don't. It doesn't make much difference in the big picture. There are no special tools required. Most guys use large Channellocks or a C clamp.

Personally, I open the bleeder. Over time, the dirty muck in the system migrates to the lowest point, which is the calipers. I like to open the bleeder so it flushes the dirty fluid out and new fluid replaces it. There are also good arguments to definitely open the bleeders on later model vehicles. If you don't, the contaminated fluid can get pushed back up into the uber expensive ABS controller. Not good...