For restore MFC in the new network you need to export the private keys from old wallet and then import the keys into the new wallet.
To export (import) a private key from your MFCoin Desktop QT wallet wallet:
launch your MFCoin-qt wallet as usual and wait for it to full load the blockchain and start up
click on 'help' in the menu bar (top right)
click on 'debug window'
select the 'console' tab
type: walletpassphrase "your walletpassphrase here" 600
for export key type: dumpprivkey [your MFCoin address here]
for import key type: importprivkey [your private key here]
this will return the private key, you can copy it now; ensure you clear your clipboard/history afterwards
To export a private key from your Android wallet wallet:
Settings -> Show recovery phrase
Go to https://mfcoin.net/recovery_tool
Input your recovery phrase to textbox "BIP39 recovery phrase"
Find your private keys below on the page in DERIVED ADDRESSES
To export a private key from your web wallet wallet:
Click gear icon (top right)
Click Export private keys