This is how simple it is to convert to the internally regulated alternator.
You can use the 10 SI alternator or better yet one like I pictured off a mid eighties GM truck or car called a 12 SI.
You will need to get the small plug that plugs into the side of the alternator off a car in the junkyard, or you can buy the plug at autozone for a few bucks.
Then just hook the wires as shown.
This is the normal three wire setup which I recommend. If you get a one-wire alternator then all you have to do is mount it, and connect the battery wire to the back, nothing else needs to be done.
You have a 12 gauge red wire on the old alternator and it will work if you don't have a lot of auxiliary stuff. Just reconnect it to the back of the new alternator and plug in the plug after you have connected the wires to the regulator plug. You won't need the small blue and white wires with the old plug.