As long as you keep your private key (txt file) and you dat file in a location known to you, you can simply import the dat file into the new wallet version. If you don’t feel confident in doing this:
Make sure you get your private key. You can generate this when inside the wallet. The private key will be generated and stored in a UNSECURED txt file with the name UNSAFEX[number]. Make sure you keep this very secure as this is the funds in your wallet sent to the public address you used (If you have used more than one public address, the file will generate also more than 1 private key). To be super secure, break the initernet connection before you generate the private key. Print it, delete it from your system and KEEP the private key secure.
See below how to do this:
“Export encrypted…” generates the dat file (make sure you remember your password)
“export unencrypted keys” generates the txt file.
Here’s some additional help: https://www.youtube.com/watch?v=Z7a2XL8EfGw