To open Pack-a-Punch in Blood of the Dead, we need to create the Spectral Shield. First you need to power the whole area to open the gate to Catwalk and activate teleport pads.
You will start at the Richtofen’s Laboratory, go up to Model Industries, open the gate to West Grounds, and go straight. In front of you is the way to Catwalk, and to your left is the gate to Power House.