it's all glue, no need for bolts etc
I fitted the aero spoiler myself, and it hasnt fallen off yet
1) make sure the area is clean
2) use the wet/dry sand paper and just give your roof a quick sanding (Lightly) and then do the same on the spoiler
3) time for the Glue, it's very messy so make sure you have a good area to work at and also a damp cloth, then it's a matter of lining up the spoiler, I have mine resting on the black trim around the roof and it looks good
4) when you have the spoiler in place and it glued, use some tape, (masking or duct) to hold it in place until the glue sets it needs about 8-12 hours so make sure u dont need to go anywhere,
I done mine on a Sat evening, went out for the night, had a few drinks, and then come Sunday afternoon after I had recovered the spoiler was firmly in place
hope that quick " How to do" helps, if you use the search feature I think you will find some pictures and other guides on how to fit the spoiler aswell
Jp