How to add from the Wallet itself
1. Click the Extension icon in Chrome to display Wallet, and press the Account icon in the upper left corner of Wallet
2. When the account list screen appears, click "Add Account...
3. Click on "Import Private Key".
4. Enter your account name and the "Private Key" of the account you want to import, then click "Import Account".
5. Added to the account list screen
How to add it from the settings screen
1. Click on the Extension icon in Chrome to display Wallet, and then click on the "gear icon" in the upper right corner of Wallet
2. Go to the settings screen and click "Account" under "Wallet
3. Click "+Add Account" in the right menu
4. Select "Import private key" from the list of ways to add an account.
5. Enter a name of your choice for the account name, enter your private key, and then click "Import Account.