Oh, sh!t. Now the mirror is broken. We (me and my car mechanic) were able to detach the adjuster motors, but pop out the centre ball joint was impossible. I have asked the GM dealer twice how to do this.
And (same as Roy) he said: Take the screwdriver and pry out the frame!
But on Euro model mirrors things are somehow different . The mirror glass frame is fixed to the motor bracket with a screw from the front.
You have to take out the glass itself first, if you want to detach the glass holder frame.
I was really angry with the GM dealer and I complained to him.
Now he wants to give me a complete new mirror!!
Hope he does not change his mind!
Gunnar