I just did this!

https://imgur.com/gallery/RJ4ETv0

We had a catastrophic failure of one battery, so we bought a whole new set at Sam's Club and I took the opportunity to install the new cables (2-gauge) that I've had sitting around for a while. The old cables came off with a 1/2" wrench, nothing complicated, the only thing that I found "tricky" was documenting the motor-to-controller connections since I didn't want to be left guessing. After installing the motor wires (much easier with the batteries removed, but might be possible with them in) I dropped the new set of batteries into the freshly painted battery tray. Since the batteries were out, I cleaned up the rusty battery tray with a wire wheel and hit it with a can of Rust-Oleum rust convertor. I installed the new cables one at a time, and once I was finished I hit all the posts with a dose of CRC Battery Terminal Protector to keep things looking nice and functioning as designed. The only downside to the new cables was that the controller-cover doesn't fit, but I'm going to pull it out once I figure out an elegant (3D printed) solution to the tow/run switch location.

I also installed a new voltage gauge, since the old one was the bar-graph style that was basically worthless. I had already run the wires for the old switch, so it was a simple matter of enlarging the opening a bit to fit the new gauge. I like the new gauge much better, it is always on so I can see what my resting voltage is on or off the charger, and see how much my voltage drops under load.

Now for the bad news. I don't think your battery cables are the likely culprit in your golf cart. New cables will look great under there, but the cables (unless they're really bad) are not going to cause the symptoms you describe... it sounds more like weak batteries. How is the water looking in them? What voltage are you seeing when fully charged? My old set of batteries (Crown) were on their way out before the one exploded under our seat, they were really weak on steep hills and went through distilled water like you wouldn't believe. Obviously your new cables would work on a new set of batteries in the future, but you'd be re-doing all the labor if you find out the batteries need to be replaced after you swapped new cables onto the existing ones.