Honestly, you cant
Unless you feel comfortable going in and editing the drivers .dll files and such. I personally don't. Just so you know, that being a 6xxx series card most of the optimizations have been made already. The only big performance gains you will see are in the 7xxx series cards, and most likely in the high end 7xxx cards.
Honestly tho, I would expect less than a 5% difference (if you are getting 60FPS in a game, you now would be getting 63-65FPS not really that big of a deal) I HIGHLY suggest that you use HP's drivers, cause usually they not only edit the AMD's drivers, but also Intel's chipset driver, and then xxx's audio driver, and then this piece of software and then this.... so they all work together BETTER. So overall system responsiveness and performance will be much better with HP's drivers. HP is not a "Push the envelope" company, if you wanted to do something like that you should be looking at someone like Alienware (this is where *gulp* Alienware is actually legit) or maybe even MSI or something like that. You get what you pay for, HP is simply a "no-hassle" computer, so that is what you get, no hassle and no features or latest beta updates.