Re: Front bumper
try to focus on one corner first just to get an understanding of how they fit together. They somewhat interlock. Then gently apply force at each point you feel the clips resisting seperation on the front (near the fogs, etc). Do make sure to remove the yellow metal clips underneath first. I believe there are two plastic nuts to remove too with a quarter turn. If i recall correctly, they are near each corner underneath.
Do a search here for the link on the custom lower mesh grille install. It has pics of the fastener locations.
2008 Grand Cherokee Limited, 4.7L- K&N CAI, Custom Mesh Grille, Magnaflow Cat Back, Mopar Body Kit, 22" Chrome SRT Factory Reproductions, Vreds, Bwoody Sway Bar links, SRT front and rear sway bar, SRT Bilsteins, WK Eibachs