How to change compact fluorescent 4 pin bulb at 22 feet
What were they thinking?  I'll tell you exactly: "the last guy" installed that bulb from a boom lift or the top of the ladder and declared mission accomplished. Never thought about the feasibility of changing it from the ground in the future. 

Rent a boom lift and change that fixture

Select one that has an Edison base aiming straight down, and that has a big enough hole in the shade that it can be reached.  And then, put no bulb in it and come down to the ground.  

Then, from the ground using a common bulb-changer stick, install a modern LED "bulb".   Do not install the first bulb from the boom lift; that was the last guy's mistake!

If this just doesn't work out with that fixture, then take it down and put up another fixture that does, while you still have the boom lift.