if you can get the front of the car jacked up you can easily install the front lip yourself.... it only requires a few bolts, some double stick tape, and drilling 2-4 holes in the bottom of the bumper IIRC (i've watched a few being installed at G-Squad meets but never did it myself)

installing trunk spoiler is another story..... you need to drill holes in the sheet metal of the trunk itself (which is something i wouldn't do). make sure it's totally waterproof, hook up the 3rd brake light in the new OEM wing, then remove the stock brake light from inside the rear window....

easiest way to add an OEM trunk spoiler is actually to trade trunk lids with someone who has it (say someone who wants to change out for a lip style one and doesn't want holes in their trunk). swapping the entire trunk lid only takes like 10 mins