If your wallet(imToken, MyEtherWallet ) has balance, then you can choose import account with the private key or JSON file
1. Import Account with the private key on the old version
1) Click menu on the top right
2) Import Account. MetaMask provides two options to import account: one is the private key, the other is JSON
3) Use private key here
4) Importing successfully
2. Import private key on the new version
1) Click circle on the right side, select"Import Account"
2) Here, we still use the private key, paste private key, then IMPORT
3) Account importing completed, you can check imported status and balance
Cautious: With JSON file to import, you have to enter the password when you created the account.
Thanks for your support!