I guess i missunderstand the #4 post cause you said anything like restore the old wallet but i would like to know if the same process can be use for other BTC wallet (electrum).
That's off-topic but yes, you can.
But Electrum's wallet file doesn't have to be renamed to be loaded by default, you just have to paste it to the data directory:
%appdata%/electrum/wallets then open it using 'file->open' menu even if Electrum is running.