How to import wallet.dat.txt file, to convert a txt document into usable BTC? this will be my first time posting here so please forgive any newbyness.

A friend recently gave me an old thumbdrive with a wallet.dat.txt file on it. He had bought a full BTC but didn't know what he was doing or how to spend it so he said I can keep it if can figure it out.

I'm semi-familiar with BTC but know almost nothing about paper wallets/cold storage. After some research, I discovered I might could import it here: https://blockchain.info/wallet/import-wallet

However, I get the following error message: Unknown File Type wallet.dat.txt

I think perhaps he may have played with it trying to get the BTC, and opened the .dat with a word processor which converted the file to wallet.dat.txt

Is there any way to convert the wallet.dat.txt back into wallet.dat? Or is that even the problem here?

Just trying to get at that free 1 BTC. Please help! Any/all advice is welcome!
I'm not sure how it got renamed with a .txt extension, but if you are in Windows and have the "hide known file extensions" setting on, than the file would appear to be named 'wallet.dat' since it will hide the '.txt' portion.  Remove the ".txt" from the end, and try again to import the wallet file.