I can't remove the back light cluster on the back door of my toyota granvia to change the bulb on the stop light. Pleas help

I'm not familiar with your vehicle, but you likely need to remove an inside panel for access.

I have removed the back panel off the rear tail gate, and you can see were the bulbneeds to go but the space is very tight toget the bulb in or out. I have tried to pop the cluster off from the side, but something seems to be holding it back. Any ideas . Thanks

Even though this link is for a Taurus, it may help you with replacing your rear bulbs:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post2092806

The procedure is pretty much the same on most cars.

You need to remove the liner panel inside the door (first take out the two plastic screws in each lower corner) then 'pop off' the retaining lugs all the way round, plus three more in the middle. Then romove the clear plastic moisture sheet - fixed on with black mastic all round the edge. Now locate a round hole in the inner metalwork - situated behind the reversing light - this has a 10mm bolt on a long thread. Remove the nut and push the threaded bolt out towards the outside of the tailgate.
(It may need a tap with a piece of wood and a hammer). The from the outside, prize off the light unit from the outer edge and it all comes loose.