Rather than try and replace all the front and rear signal bulbs etc. , I think I'll remove the annoying "bulb out" indicator light in the dash. All of the bulbs are working fine and the garage suggested that I would have to replace them all to hopefully correct the problem. I did try replacing the front turn signal bulbs but no luck. It still comes on when I use the right turn signal or the parking lights. How is the best way to remove the the bulb in the dash ? It's the fourth one from the right side. ( 1990 780 Bertone )

That is there for a reason :)
But, if you do remove it, and drive around, how will you know when a globe isn't working (of course, a blinker goes fast when it's blown, but what about brakes?), i suggest you keep it in, and trace the ground (like others said) from the blinker, and clean it up, it could be an idication that other problems, such as funny engine problems (due to bad grounds) are coming up...
Just my .02 cents.
Az

I had a same problem. Try looking at the relay that controls all your lights. It's the big round red one. Open it up and see if it needs to be re-soldered, that was the case with my relay. If you can't find where your relay is damaged, you can go to your local junk yard and pick one up for $10.

If this happens when you use the directional OR the parking lights, then you probably have a bad ground to one of the right-side light assemblies. A common place on the 780 is the ground wire to each rear light at the push-on connector inside the light assembly (not the eye terminal under the bolt). Pull the terminal off the blade, squeeze it just enough to make a snug fit and push it back on.