[DONE] Bitcoin Update

I have been using 0.8.5 version of Bitcoin (I can't remember how I installed it but I know it was luck). This morning my wallet showed a warning message that my node software was out of date and I was at risk. I checked MCC and found an updated version (0.9.3) so I installed it. Ran it again but still got the warning message. I checked the Bitcoin website and it showed the latest versoin as 0.10.2 so downloaded the tar.gz file. Not being technical I am at a loss as how to install it. Using Ark to extract the files it shows bitcoin-qt. Do I just overwrite the current bitcoin-qt file in usr/local/bin?
Many thanks.
Many thanks.