How do I....

yes they are held in by push clips you can use a small screwdriver and carefully pry at sides outward and they will pop out doing it this way you take a small chance of breaking them if your not careful. another way to remove is to remove the whole dash console, its simple, you remove the panel at the bottom containing the shifter and boot it just pops out pry carefull at the top corners and pull it out far enough to expose the two bolts located under shifter and boot panel remove those two bolts and cigarette liter wires then you will remove the two rubber bumpers and two screws in the storage compartment under the radio look closely at the topside of this compartment you will see the screws remove these and the panel containing the vents will pop out then push on the backside of the vents they will come out...goodluck....and also a repair manual will tell you all this info.... there a good investment....
 
why not just carefully pull the vents from the original cage by getting a flat screw driver and carefully working each end out then with both vents out grab onto the center of the vent cage and pull, if it's still stubborn while pulling on the center section lift up on the 8 tabs that hold it into the dash... hope this helps