Everything else is staying the same. Old/new video cards/CPU are both AMDs. If uninstalling/reinstalling drivers is recommended (just graphics, more than just graphics)?
GPU - YES. (Uninstall driver while your still running the old card.. shut down the PC.. install the new card.. boot and install new drivers)
CPU/RAM - NO.
Generally you don't need to install or uninstall something if you change your CPU and/or memory AKA RAM but graphics card. You have to uninstall old drivers with an excuse; if they are in same family. Like you have had HD 6770 and upgraded it to HD970. But it's highly recommended (I assume) to replace drivers for your graphics card.
GPU - YES. (Uninstall driver while your still running the old card.. shut down the PC.. install the new card.. boot and install new drivers)
CPU/RAM - NO.