In fact I do. His sludge built over many miles. Everything in my post is true. Stop being so agitated and think things through.

https://www.doe.mass.edu/mcas/pdf/2011/225502.pdf

It looks like 65% antifreeze is ideal.

Check the bottle labeling to see what the feeeze point will at 65% concentration. If it isn’t low enough drain the antifreeze water mixture and refill with water or antifreeze to get the lowest freeze temp. The freezing temp goes up again as more antifreeze than the optimum amount is added.

Looks like the engine has been running hot for a long time. I’ve seen it before. Because the electric fan did not pull enough air. The knock is not necessarily a deal breaker. If it’s not severe and you don’t run the car hard, it may last a while. It will still knock though. My friend’s lasted 2 years before he sold it. Oh, and fix the cooling issue and change the oil a couple of times.

No grinding. Separate the bearing housing then you’ll have the room to slide the stud out. 4 bolts from the backside.