68 Barracuda Gauge Cluster Removal

the procedure is found in factory service manuals. Those are free downloads ( search for them as I don't have the link ).
About rotating the instrument panel face downward... If it aint pulled out of the dash far enough first, you will very likely break the very top of the 3 contact pins from the left hand circuit board.
The right circuit board hangs over past the edge of the inst' housing at BRAKE indicator lamp so its too easily broken there. These are the kind of tips you get from forum members experience. "how to" comes from service manuals. Good luck with it.