Answer: If you can no longer access your external, self-managed wallet, there are several ways to restore it with the help of your pass phrase (12 or 24 words) or private key. The step-by-step plans below are of the most used Ethereum and Bitcoin wallets at the moment. Always check the instructions of the wallet you are using.
Metamask Wallet (pass phrase)
1. After installing a MetaMask wallet, click on 'Import Wallet'.
2. Enter your secret recovery phrase.
3. Choose a new password and click on "Import".
Trust Wallet (pass phrase)
For this example, Trust wallet is used to import a pass phrase:
1. Follow the steps in the link below to restore your Trust wallet.
https://community.trustwallet.com/t/how-to-restore-a-multi-coin-wallet/43
Exodus Wallet (pass phrase)
For this example, the Exodus Wallet is used to import a pass phrase:
1. Follow the steps in the link below to restore your Exodus wallet.
https://support.exodus.com/article/42-how-do-i-restore-from-my-secret-12-word-phrase