As you may already know, ETH-wallets are just user-interfaces to access the blockchain. This means you can just export your private-key from any ETH-'wallet' and use it to log in to another 'wallet' (interface) like MyEtherWallet or Metamask without creating a new address and transferring your funds.
I just created this small guide on how to export your private-key/keystore-file/mnemonic phrase from ImToken, Jaxx, Eidoo or Parity.
ImTokenThere are multiple ways to export your private-key to use it for logging in to MyEtherWallet or Metamask.
1.) Mnemonic Phrase (easiest)Go to 'Profile' > 'Manage Wallets' and select your wallet.
Now select 'Backup Mnemonic' and enter your password.
Write down the 12 words on paper.
2.) Keystore-File (most secure)Go to 'Profile' > 'Manage Wallets' and select your wallet.
Now select 'Export Keystore' and enter your password.
Copy the content of the box and create a new file called 'keystore.json' by using your favorite file-manager (e.g. ES File Explorer) and paste the previously copied content and save the file.
Now transfer the file to your PC (you should prefer a USB transfer for security-reasons!).
3.) Private-KeyGo to 'Profile' > 'Manage Wallets' and select your wallet.
Now select 'Export Keystore' and enter your password.
Write down your private-key on paper.
JaxxThere are also multiple ways for exporting your private-key.
1.) Mnemonic PhraseOpen the menu in the upper right corner > go to 'Tools' > 'Backup Wallet' > 'View Backup Phrase'
Enter your PIN and write down the 12 (orange) words on paper.
2.) Private-KeyOpen the menu in the upper right corner > go to 'Tools' > Display Private Keys
Enter your PIN, select 'Display Ethereum Keys' and write down your Private Key on paper.
EidooGo to 'Preferences' > 'Backup wallet' > 'Backup now'
Enter your password and write down the 12 words on paper.
ParityGo to 'Accounts' > Export (on the right side)
Select your account, enter your password and click 'Export' in the bottom right.
The downloaded file is your keystore-file.
----------------------------------------------------------------------------------------------------------------
In general you should always prefer using a keystore-file. It's an encrypted version of your private-key so you also need to enter a password to access your wallet. I created a guide on how to create a new keystore-file if your previous wallet doesn't support exporting it by using your private-key or mnemonic phrase.
For more information check this link:
https://bitcointalk.org/index.php?topic=3014688.msg30996799#msg30996799
Regards,
Nestade