Thanks for answering..really appreciate it..
Basically i just done back up for both Bitcoin and Litecoin and have 2 files called wallet.dat (files i uploaded to usb stick )

If i understand this right if i download new version of Litecoin and Bitcoin i can just replace existing wallet.dat with the previous ones.(kind of over ride them)

The only thing i cant get figure out how to do that on Mac ..since i dont have folders like on Windows platforms.

I have downloaded Electrum Bitcoin Wallet and Litecoin-QT but not sure how to upload  those wallet.dat files ...


Was watching this video on YouTube

https://www.youtube.com/watch?v=jGXf2xFyWaE

and it looked straight forward on Windows..hopefully should be easy on Mac too..