What happens next?

How to install a factory navigation radio into a 2002 2004 jeep grand cherokee 
Start by using a pry tool to pry the radio bezel surrounding your jeep's factory radio out from the dashboard. 
Set it aside, you'll need it later. 
Your jeep's factory radio is held in by four (4) philips-head screws.

pick from the following. [I] Separate them to expose the filter, if there is one there. After loosening these, your jeep's factory radio's entire dashboard should come out. [II] ( from where you can access them you'll need the screws aren't unnoticeable. Take the spring at the front of the dashboard with pliers and release the clips. [III] Remove them and set them aside, you'll need them later. Remove the dashboard tweeter bezel by using a pry tool and set it aside. [IV] One philips head screw is for every 12 inches of space between the front of the cabin and the dashboard, and has a 1.500l height (3009.8 inches). Screws matching these are needed to mount the unit to the dashboard.
[III]