1995 chevy tahoe timing 7 degrees retarted.. how do i set the timing

You need a timing light and you have to take the cover off the electrical junction on the passanger side of the firewall once the cover is off you can disconnect the timing advance wire theres onle two wires you can disconnect so you cant mess it up the other one has a fuse in it for the lamp under the hood. then under the distributer theres a 9/16 bolt that holds a clamp on the distributer to keep it in place loosen it up just enough so you can turn the distributer but it still stays in place. then take some clalk of a yellow or white crayon from your kids and look at the crank shaft there will be a notch in it use the chalk to highlight it. then hook up the timing light pos-pos neg-neg and the clamp on the no 1 cylinders plug wire the the no 1 cylinder is the closest cylinder to the radiator on the drivers side. then fire it up and hit the button on the light you will see it light up as that cylinder fires and that notch should line up with the timing tab on the front of the block to adjust the timing just rotate the distributer until the notch lines up with the tab. let me know if that helped.