walletpassphrasechange "oldpassphrase" "newpassphrase"

The walletpassphrasechange RPC changes the wallet passphrase from 'old passphrase' to 'new passphrase'.

*bitcoin-cli help walletpassphrasechange

walletpassphrasechange "oldpassphrase" "newpassphrase"

Changes the wallet passphrase from 'oldpassphrase' to 'newpassphrase'.

Arguments:
1. "oldpassphrase"      (string) The current passphrase
2. "newpassphrase"      (string) The new passphrase

Examples:
> bitcoin-cli walletpassphrasechange "old one" "new one"
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "walletpassphrasechange", "params": ["old one", "new one"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/