backup your wallet.dat to multiple places... -- important thing to always do, constantly!!!!!!
to access it its in (if windows 7)
goto run, type in %appdata% then goto bitcoin folder.
run installer for new bitcoin version.
your original wallet.dat should still be in the same spot, but if not, replace with backed up copy.
thats all i did and seems to be working fine.
long as you back up your wallet that is the main thing.
if data/block chain is corrupted it can be downloaded again (yes it takes a long time) but no funds lost if you have to.
I have been pondering on this for a while and now i understand how to go about it.Thank you.