As you can see in the picture, the oil pressure switch in this Bronco II had been leaking oil for a while, the electrical connector was broken, as a result, the oil pressure gauge didn't work in this Bronco II.
The space is a bit tight, but there is enough room to insert an open end wrench to remove the old oil pressure switch . ( sending unit ).
To make sure that there will be atight seal, cover the threads with teflon tape prior to installing the new oil pressure switch, that way there won't be any oil leaks.
Clean the electrical connector and plug it to the new oil pressure switch.
Start the Bronco and watch the oil pressure gauge, the oil pressure should be within the normal range.
Watch for any oil leaks on the new oil pressure switch as you allow the engine to run for a few minutes, if you don't see any oil leaks you are done.