While installing the grille is highly DIY-able, putting the lip on the car is a different story.  We strongly recommend having a pro shop do it for you.  It is also recommended that painting comes afterwards.  With all that said, we gather there are highly skilled owners, who, with the help of ample 3M automotive adhesive tape (the dark grey foam tape with red lining), will do a great job fitting the lip to the bumper.

Importology Lip Install Instruction