Question: gpg how to export private key?
Answer: Identify your private key: Copy. gpg --list-secret-keys user@example.com. Example output: ... 
Run this command to export your key: Copy. gpg --export-secret-keys YOUR_ID_HERE > private.key.
Copy the key file to the other machine using a secure transport ( scp is your friend).
To import, run. Copy. gpg --import private.key.