.....erm.....the answer to that can be kinda tricky, tbh. From my experience on this, I have found that the less complicated your rig is the more likely that you won't run into issues simply installing right over the old version. I would always take the long route on my main rig of uninstalling CCC....rebooting into safe mode and running Driver Sweeper (now Driver Fusion)....reboot back into the OS....installing the new driver....rebooting a couple of times.....resetting up all my personal preference settings....rebooting again. I did this to try and rule out any issues that may have popped up...for me I just felt safer going the long route.
On my wife's and son's computers, they have simple hardware setups...no crossfire....no top of the line GPU's so, I haven't found a need to go the long route....I just install the new right over the old, no problems. They don't play games though so I can't say for sure that there are not any hidden issues that I am not aware of hiding in the background. 
Only advise that I can give you is....try installing over the top, followed by testing....if there isn't any issues, you should be fine....if you have issues pop up, take the long route. Most importantly though, if you are not experiencing any issues with your card(s), then don't installing a new CCC version....no reason to. 
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Requiescat In Pace AMD Processor Forums | Member since: 1/19/2009 | Post count: 4142
Please don't PM me with questions, instead create a thread so that everyone can assist and benefit from the knowledge provided. Thanks in advance!