When opening Electrum you’ll be greeted with a list of options. (Existing users must navigate to File > New/Restore).
Select Restore or import a wallet and Hardware wallet.
TREZOR is currently the only hardware wallet supported by Electrum and is automatically selected in the next window.
Enter your TREZOR recovery seed.
Input your passphrase if you used one. Any passphrase will create a valid wallet. If your wallet shows a zero balance, restart the process and double check that the passphrase was entered correctly.
You can now send any funds that were stored on your TREZOR.
Note that the private keys from your TREZOR seed are now stored in Electrum. Your funds should immediately be moved to cold storage. The old TREZOR seed is now insecure and should not be reused.