There's a template that you need to make the job easier. It will take about 40 minutes to put the OEM spoiler on with the template...without it, it will be more difficult.
There's 4 holes in the lid. The outer two are the ones that actually hold the spoiler on. The inner two (which are huge holes to drill) have plastic guides that are more of snaps than bolts. If i had to do it again I'd take the inner ones off and not drill the ohole are rely on the double sided tape and outer two holes.