How do you change the clock on a 1996 chevy van, g-30?

how do ya change the clock on a 1996 chevy van, g-30?
Change the clock? You mean for DST? On a factory unit?
There is usually a pair of buttons on the right hand side of the unit: one "H" and the other: "M"
Press and hold either of these buttons for a few seconds... the display will begin to change, first slowly and then somewhat faster. Both of these buttons can be used to reset the time until you're at you preferred time setting. (I usually add five minutes or so, to be sure I'm not late for things... )

Mine has knobs, but not those buttons, thank you anyway.