Searched - How do I remove the Fuse Box?

I need to change my fuse box inside the cab as the clutch cylinder leaked on it a few years back and now it's all rotted.

The panel is in my '89 and under the dash on the driver's side, mounted next to the side panel. I found the 2 long screws that mount it and have it loose, but I do not know how the wires actually attach to the back of it. I cannot get in there far enough to see what is behind it.

Is there a clip on the back that I can undo the wiring harness and just swap or do I need to get a manual, cut the wires and rewire the new panel? I don't have a manual right now so any link with pics would be much appreciated or any direction at all. I don't want to just yard it out of there as it needs to run afterwards :laugh:. In a perfect scenario I am hoping it is just a quick swap.

Thanks in advance.

there is a small bolt on the back side of the harness at the engine side of the firewall.The fuse box is hardwired so a quick swap is out of the question...is the plastic of the fuse box ate up?
I was going to do a box swap on my 89 but realized it would be more trouble than just dropping the fuse box and replacing the few terminals that were causing problems with new terminals.I got a motormite add on fuse panel in the electrical isle at the local parts store and robbed the terminals out of that....only cost about 5 bux.
I recommend that while you are in there to look closely at the wires for corrosion.In my case the corrosion was climbing up in side the wire under the insulation!!!
I cut back into the wire untill all the corrosion was gone then I spliced in new sections and added new terminals.Corrosion=heat...heat baaaadddd.....

If you have anymore questions feel free to private message me.....