Need help on B2 4.0 swap

[TillamookB2]

I'm taking the 2.9 out of my 88 Bronco II and replacing it with a 4.0 from a wrecked 1991 Explorer I bought for $200. The Bronco has an M5OD that will end up behind the 4.0.
Anyway, I'm trying to get the wire off the side of the oil pan, which I believe goes to the oil level sensor. Its so caked in grime, I can't tell if it screws off, pulls off like the oil pressure sensor, or has a tab. I've tried to pull it off with a pair of pliers, but it wasn't moving. I can turn it, but it won't come off.
Also, I don't know how to deal with the A/C. I'm completely poor, so I can't take anything to a shop unless there is no other way.
I'm sure I'll have more questions as I go along. Any help would be awesome.

 

[adsm08]

Clean the oil level sensor up a bit. There is a butterfly pin kinda deal that that holds it in. You spread the pin and pull it out and the wire pulls right out of the pan.