Thermostat replacement replacement instructions please?

I†m having problems replacing the thermostat on my 2000 Buick Century.
I can’t remove the upper bolt on the Thermostat Housing; I don’t know if it’s frozen in place or, I just can’t reach it well enough to get a good grip on it (or both). There are two horizontal pipes in the way, one’s black and the other’s silver. I tried †liquid wrench’ on the bolt and gave it several good taps, but it won’t budge.
To access the bolt better, I tried to remove the Throttle Body. I removed the nut on the lower right side of the TB (in front of the small black plate that’s attached to the black pipe). However, I can’t seem to remove the stud bolt that comes from the Throttle Body and extends through the slot in the small black plate.
I’m wondering if I should try to remove the black and silver horizontal pipes that are blocking access to the upper bolt on the Thermostat Housing. If so, I’m not sure how; I can’t find any info on how to do it. By the way, the lower bolt on the TH also seems be frozen or, I can’t get enough leverage (or both). I would appreciate any advice that anyone can give me. THANKS!

3.3 v6 thermostat removal