It's not your computer, the link is broke for me as well.
Go to the search option at the top of the page and type in Seatbelt ding
the first one that comes up gives the instructions.
or i think its page 45 in the manual.

 

Just wrap the belt around the back of the seat and plug it in to the receiver

 

read ur darn truck manual it tells u a procedure how to get the buzzer to stop making noise....