Two 3/8 nuts on each side and one 1/4 screw around switches area
Remove heater valve cable and vacuum lines.
Everything can be made under the dash with cluster in place. Depending on your flexibility and tools available can be a easy or harder job.
Small 1/4” drive ratchet with extensions, or flex will make it.
The trickiest is the 1/4” hex screw for the rear holding bracket due the harness being around.
Another 1/4” screw Can be removed from heater control too, keeping the bracket attached to cluster, but that could make harder to reinstall with bracket being in place. So IMHO, better keep the bracket attached to heater control. On this I think is a matter of preference on what to deal with.
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