Its important everyone downloads the new version wallets ASAP.
Simply download the new wallet, close your existing wallet if its open, then run the new wallet.This wallet can be overwritten on top of your existing version. Your wallet balance should remain unchanged after installing the new wallet.This is a good time to take another backup of your wallet.dat file for safe keeping (Not required but backing up your wallet regularly is always recommended )
But the wallet.dat stays thes same? Because I have the wallet.dat at a safe place and I am not using the wallet at the moment at all. Or do I have to install the new wallet just to backup a new wallet.dat?