Water pump replacement lessons

I figured I would tackle replacing the serpentine belt, water pump, and flushing the coolant myself. How hard can it be? It wasn't a bad job to do and there are a bunch of DIYs to help. While I was going through the ordeal, I figured to upgrade the pump with a Stewart and install Turner MS wp and power steering pump underdrive pulleys. There are plenty of DIYs so I'm not going to go through the whole process, but rather just touch on a few "challenges" that I faced to help others.

1. I followed the Bentley manual too strictly and paid for it. The manual says to loosen the serpentine tensioner by turning clockwise. Yeah, that is if your tensioner is mechanical. If it is hydraulic, to remove it you loosen normally. So yup, I snapped the bolt. And spent about 2 hrs with a drill and bolt extractor getting it out. Super fun.

2. I should have ordered a (hydraulic) tensioner ahead of time, because once I looked at it, I wanted to replace it and I ended up buying one locally Prestige BMW, which is the biggest ripoff. Every time I buy a part there I swear I'll never do it again. I paid $140 for the stupid thing while Turner sells it for $75, but when you need it now - you pay.

3. Now I'm cooking, got all the parts I need and am replacing the misc. stuff along the way and am getting the new serpentine belt on. The tensioner: I understand its purpose, but I think it is not great. The a/c tensioner in my car is mechanical and is so easy, turn the adjuster and it relieves tension, ie. tensioner. The hydraulic version, not so much. For the life of me I don't know how to relieve the tension, therefor getting the belt on correctly is damn near impossible. I ended up using the upper idler pulley as a tensioner; because it has an offset bolt I was able to get the pulley almost all the way on, then rotate it so that the little nipple slipped into place, then fully torque it. Like I said, I'm not sure if that is really how it is supposed to be done, but it was the only way I could think of.

4. Finished. Did the whole fill and bleed coolant process. Easy. Start to finish was about 7 hrs because of the "fun" I had. Took it for a spin to see how I'd like the underdrive pulley steering feel. Yeah, no noticeable difference. So a bit of a waste, but I'd never know unless I gave it a try. I've now been driving for about a week after completing the work and haven't had any issues (phew!)

There you go. My 2 cent version of things I learned. I hope you don't make the same mistakes I did

What do you mean "loosen normally" for they hydraulic tensioner. I have a hydraulic tensioner on my 01 325i and I put in an 8mm Hex socket with breaker bar and turn it clockwise to loosen the tensioner