AFAIK  you click on settings in wallet then click on encrypt wallet and create password, make sure password is
1: Strong
2: Unique
3: Copied to a safe location......This is most important, if you forget lose password you can't access your coins ( I stuffed my next password and it cost me heaps)

After restarting wallet click on settings then unlock wallet. Enter password making sure the "For staking only" box is ticked

you should now be staking safely.

Make sure that you backup your wallet.dat file to a safe location

Hope I've got it right and it helps

Jon