tighten out side mirror

There is lock ring that holds the glass to the housing. You can get behind the end of that ring with a small screwdriver and remove the ring and then the glass comes out. Most of the ball retainers are held in with rivets though....
I have found that a couple of drops of superglue on the ball works well to tighten a loose mirror. Protect the door below in case you accidentally miss with a drop or two. Put a couple of drops on the ball so it goes into the housing and let it harden over night.. Go out in the morning and adjust. This is one of the few things that I have actually found super glue useful for. Try it, you will be surprised. And it lasts a good while too.