Frayed Cables to Car Battery: Easy DIY?

Went out to start my car, nothing happened. Popped the hood, found several small wet tree twigs that were sitting on the battery. It looks like they shorted some cables that go to the battery (not the cables going to the terminals). I’ve included pictures of each of these. It looks like the large frayed one(red arrow in photo below) is simply a ground that connects to the chassis, which should be easy enough to replace by myself as most auto places have something like that in stock. The other smaller one (green arrow in the attached photo) containing multiple wires also looks messed up, so I’m assuming that also needs to be replaced. So I guess I have two questions: What is the name of this smaller cable set, and is that also something that is easy to replace? I didn’t trace the cable, but it seemed like it had a fairly long path. Thanks!

Looks like the positive and negative cables need replacing.

Tester

Not frayed, chewed. You had a critter living rent free in your engine compartment. The wires to the green arrow can be exposed and repaired with a wire of the same size. Solderless crimp connectors can be used to repair. If there is a connector body under there, replacements are available with 6 inch pigtails.

The battery cable looks corroded, not frayed. But hard to tell under that nest of trash.

Ah, good observation. That probably explains how the twigs got in there.