To import the Metamask wallet, you need to first find the Public Receive address for the wallet. Wallets may have more than one account, so you will need to do this for each account in your Metamask wallet.
Click the "Copy" button for each account on the wallet to paste to ZenLedger.
Once you have done this, go to ZenLedger and navigate to Wallets/Import tab and then Wallets import tab across the top.
Scroll to the bottom and select "Others" for your wallet type,
Click the dropdown and select ETH/ERC-20 as your coin type. You can type in Metamask in the optional description field if you wish.
Paste in the address, and then click "Yes" to the wallet being in the US (if you are) or "No" if you are not.
Click "Add Coin". If you are done adding addresses now, you must click "Next Step" to import.
Verify that your transactions are in by checking in the Transactions list after your import is complete.
Here is a video tutorial: