Seatbelt and rear climate control repair

So as most of you are aware (or if you're not you are now)
the 2004 Chevy Tahoe has 3 rows of seats and a rear
climate control.

The problem with seatbelt is on the second row both the
driver side passenger belt abd passenger side belt are
stuck in an outward locked position. I have 4 kids. I can
not allow this to continue to be a hazard to our health not
only that but it is illegal to transport my children in them.
The question is how do I get those panels off in order to
replace those mechanisms.

As for the climate control i am having a bit of a problem
both front and rear. The temperature control knobs in the
front will skip around as though it is picking up random
signals or something and making it really hard to set the
temperature to a comfortable level also the car won't
actually start getting heat in it till about 80 or 85 that
might just be because of me but im not so sure about that
I think it is more likely a problem with the vehicle.

As for the rear it is stuck blowing cold air no matter which
control unit I use to adjust the temp in the rear. So I am
relying on heating the truck solely with the front air vents
which makes for a really cold ride in the back seats.

Detailed repair instructions would be greatly appreciated
and please serious answers only.