Cardano FAQ
From Organic Design wiki
How can I import a Byron wallet into Daedalus from an SQLite file?
First you need to use sqlite3 to view the root and hash fields of the private_key table for the wallet in question, and the run Daedalus and use netstat to check what port it's node is running on. Of course this will not help in the case of retrieving ITN funds in the main net, but it can at least prove that the wallet file is intact and whether or not you have the spending password.
cd ~/.local/share/Daedalus/mainnet
curl -H "Content-Type: application/json" -kE tls/client/client.pem \
-XPOST https://localhost:PORT/v2/byron-wallets -d '{ \
"style":"random", \
"name":"NEW_WALLET_NAME", \
"encrypted_root_private_key":"ROOT_KEY", \
"passphrase_hash":"HASH_KEY" \
}'