How do i get air to my rear air shocks on my 91 buick park ave? on 1991 Buick Park Avenue

The rearend sags and occasionally drags the ground, Im pretty sure its a lack of air in the air shocks, but don't know how to air them up or if there are non air shocks that can be used

2 answers
air ri you should be able to buy regular shocks from any parts store
agree with goodguy