TREZOR: Making a Back Up
All you need is the 24 seed words that you wrote down when you first initially setup the TREZOR. You can use the words on MyCrypto to recover your ETH/ETC/Tokens.
If you used any passphrases on the TREZOR and used any ETH/ETC/Tokens with a passphrase protected wallet, then you will also need the relevant passphrase.
Do not store these recovery words on your computer, as it will be just as unsafe as using a normal private key. Always write it down physically using a pen, on a piece of paper only you have access to. Also do not take a photo of your piece of paper.