The plastic rivets are non reusable, you need a tool like this one to set the new ones
http://www.amazon.com/Marson-48000-K.../dp/B00137PEPK
There are 4 bolts holding the tabs on each headlight, two at the top an two at the bottom. There is also an additional bolt at the bottom of the headlight housing. If you yank on the headlight without getting all the bolts, you will break the tab. (look at my picture you will see where the tabs are).
For the passenger side headlight, there is a bracket that needs to be removed first, you will see what I mean after you remove the wheel well liner. To remove this bracket, there are two screws that you need to remove from the engine compartment
I honestly don't think you will need to remove the headlight to change the ballast though.