The inner triangle of material connects through the door to the outside assembly (including static mirror). The whole outer assembly pivots at some point on the outer half - is this what has come loose on yours?
Removing the 3 Phillips screws (while supporting the outer part through the opened window to prevent 7-years of bad luck
) will allow you to carefully extract the outer half away from the car. The outer triangular part tucks under the window rubber on the nearest edge. You need to slightly remove and then
rotate the mirror assembly to get the manual control handle to thread out of the gaiter without damaging it (too late for mine as someone has already split it
)
Can you see any breakage inside the outer part?