That is how it looked in the morning:

Every mat has to be cut in shape and fixed in where it belongs:

1
This mat will go around the
recessed light ...

2
...
first you have to stuff it in ...

3
...
"And how do I continue?" ...

4
... from the bottom and from above
around the light fixture ...

5
...
stapling it to the trusses ...

6
... and as a last step cut
out the light shape.

later

May