open your wallet
    go to "settings"
    then choose "Show seed"
    enter your wallet password as will be asking by a prompt
    copy and save passphrase (nmenomic) which are given to you
    "close wallet" form settings
    in the opening window, after have choosing your language, choose the second option "Restore wallet from ..."
    in the other opening window, paste or enter previously saved passphrase (nmenomic)
    give to your wallet a new name (or keep old name but old associated backup files need to be deleted first)
    go to next step and give to a new password (or keep the old one)
    then your wallet will be well updated and you must have good behavior now (expected balance, unlocked amount, ...)