Hi.
I can't really give you any advice as you have given yourself the answer, you need a 1/4 drive socket and extension . The screw is just a self tapping type and as it is going into a plastic handle , it should be easily removed. I didn't have this problem when I took my handle out last year . The other problem you will face is removing the handle from the door. You have to remove the U shaped clip that holds the lock to the handle so the handle will clear the door panel. The clip just slides out from the handle but it can be difficult to see it , especially if you are using an i phone torch!
John