Crushed my fuse holder and fuse while changing battery

I crushed my fuse holder and fuse while trying to get a battery into the side slot. I ordered a fuse holder but can’t get the old crushed fuse holder out from the back. Does it screw out of the old? Why are 2 wires going to it? Are both needed? It is the middle fuse. Any idea what it controls? Thanks

The middle fuse is 30 amps and there is a nut on the underside that holds the fuse holder in place. You might have to remove the service disconnect switch to get to the nut. One wire is the power coming in the other goes to the fuse. Hope this helps.