I can't believe you guys replace those plastic spoiler clips.  No matter the cost, you can reuse the old ones.  Just take a punch and hammer and tap out the inner piece.  You'll hear it drop but, once the black part off the spoiler, shake it around and all 3 pins will fall out.  Then you just put the plastic clip back in and tap the pin in the center.
I just put the Stebro Race exhaust on my car this week.  Removing the bumper was no problem at all, I do it on a daily basis though.  The toughest part was removing the rusted bolts holding the u-pipes on.  All and all, said and done was about 7 hours.  It's the first time I've done anything like this so, I don't think that's too long.  Would I have paid a shop to do it...NO, I would've missed out on the satisfaction I got on my first drive. 
 
 
Oh btw, the Race exhaust is LOUD with alot of resonance.  If that bothers you, steer clear...I LOVE it though.