how can open the hood on my 79 corvette, won"t open?

Find someone with a long arm to reach up from underneath. Easiest way is on a lift. You can possibly get a long shafted screw driver to reach up there as well. The catch moves to the side out from under the pin head. The cable stretch and break so when you pull the handle the release fails. If you can't reach it that way you may have to pull the grille work out and remove the hinge on the driver side to lift it up side ways. to access the release manually. Also if you pull up hard enough on the hood sometimes the fiberglass separates. You'll need to glue it back together and there exists the danger the hood might just crack or break off. When you get it apart a new cable is necessary to avoid future issues. If you can get a hold of the cable between the catches you may be able to pull it to release. but again the danger of breaking the corner off exists when you lift the free side. Good luck...

where is the hood release on 1989