When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You need to pull the dash to get back there. Right side lower comes out first, then the center. Next remove the dash pad from the top and finally you can get the instrument cluster out. While it's out put a new circuit board in the tach.
You know, once you have the upper out you could probably reach in and do the bulbs. It's been a while since I did this job my self, but I think you should be able to get in there with the right and upper moved. . .
I recently took my drivers side dash out of my 69 and did not have to take out the center console. I recomend you buy a Assembly Instruction Manual (corvette central, etc.) which decribes the procedure. Basically you have to remove the little panel on the left front of the console - 1 screw. Then the dress panel under the steering column -3 screws. Then lower the steering column - easy 2 bolts. Then remove screws all around the left dash pad - 8 I think. Then you can pull the whole dash speedo and tach assembly out a couple inches and pull it down. Then you can get your hand in over the top and reach the back of the tach or speedo. Each has 4 general light sockets plus turn signal etc. lights. The general illumination sockets use gray wires. Others are various colors. Pop our the sockets. pull them out and replace the bulbs, then snap them back in the same place. You don't have to disconnect the tach or speedo cables. Be careful you don't disturb all the other connections and vacuum lines behind the dash. Before you put the dash back, start the car and make sure EVERYTHING works.