2015 Mustang GT stock spoiler (more of a winglet) removal
The purpose of this would be to install a new rear spoiler. If you just want to remove the rear spoiler for a delete look, you're gonna have some holes to cover so you might want to just look into replacing the entire decklid with one that doesn't have a factory spoiler.
Whichever aftermarket spoiler you choose, make sure it will cover the holes left in the decklid after removing the stock spoiler.
Pop the trunk and you'll clearly see two access holes in the far left and far right side in the underside of the decklid, directly underneath the spoiler. Using an extended 10mm socket, remove the nut on either side. Be careful not to drop the nuts in between the outer and inner decklid sections. To assist in this, you may want to close the decklid slightly when the nuts are almost off the spoiler bolts so they 'set' into the socket with good old gravity.
There are two more nuts located more towards inner spoiler section. You'll need to remove the trunk latch cover by gently pulling and moving it from side to side until it comes off.
Next, unscrew the rubber stops in the 'carpet' decklid panel interior backing. There's one on the left and one on the right. There are several carpet clips that secure this carpet piece to the inner decklid section but you only have to remove the two near the latch. After removing these two clips, pull down the carpet (and over the latch) until you see the the centre access hole and nuts for the inner section of the spoiler. To remove these you'll need the same 10mm socket and an extension. The access hole for both these nuts is much larger so one can actually place a finger over the nut in the socket as it comes loose - again so as not to take a chance at dropping the nut in between the exterior and interior decklid section.
Once these four nuts are removed, get a plastic edging tool (putty knife, scraper, etc). You'll need this to separate the the adhesive that bonds the spoiler to the decklid. I taped up the plastic edging tool with painters tape just for extra protection against marring the paint. You'll want to make sure the car has been sitting in the warm sun so the adhesive is more pliable. Alternatively you could use a blow dryer to warm up the adhesive to make it easier to separate.
Gently pull up on one side of the spoiler just enough so as to allow pushing the edging tool in between the decklid and the spoiler. Gently work the edging tool forward, in a side to side motion. Work your way around the entire spoiler, being careful to 'go around' the spoiler bolts that you removed the nuts from. As the adhesive gives way, you'll be able to gently pull up the spoiler and separate it from the deck lid. This shouldn't require a lot of force. If it does, you've likely missed separating some adhesive, so go back with your edging tool and work your way around again, checking for any missed sections.
After the spoiler is removed, use a gunk cleaner and rag to remove the leftover adhesive residue on the decklid.
You're done and now the decklid is ready for your new spoiler.
