How do you tighten seat ... ?

... and no, I don't mean the "buns of steel" kind.

The passenger seat backrest on my 2000 Silverado feels loose ... it flexes an inch or two, no matter how it's positioned.

How do I tighten it up so it is as rock-solid as the driver seat?

Thanks

bump

... and no, I don't mean the "buns of steel" kind.

The passenger seat backrest on my 2000 Silverado feels loose ... it flexes an inch or two, no matter how it's positioned.

How do I tighten it up so it is as rock-solid as the driver seat?

Thanks

Does anybody know how to do this? Thanks