Yeah, now I see that your description is more accurate.

I did it with my segwit wallet in the Trezor now and verified that the derived addresses are the same, so seems to work. Thanks!

Thanks for the warning. I intend to run Electrum on an offline singel-use computer that is encrypted, so should be fine.

I managed to do it with your input. However, you have to actually tick the box "Extend this seed with custom words", which seems to be the passphrase passed to the PBKDF2 function described in BIP39. I saw this checkbox previously, but couldn't imagine that it was the passphrase. Very confusing. Would strongly recommend to rename it "BIP39 passphrase" or similar, and also to rewrite the text on the "Seed extension" page that follows.

Here is the procedure, to help others:

1. Create new/Restore wallet
2. "Standard wallet"
3. "I already have a seed"
4. Enter 12-24 word mnemonic in textbox (lowercase, won't work otherwise)
5. Click Options button and tick both boxes "Extend this seed with custom words" and "BIP39 seed"
6. On the "Seed extension" page, enter the BIP39 passphrase in the textbox
7. Change the derivation path to "m/49'/0'/0'" on the next page

Hi,

I have a Trezor with a BIP39 password-protected mnemonic. Now when Electrum 3.0 is out, I would like to import this to Electrum (i.e. not connect to the Trezor for signing, but use Electrum separately). I managed to do this when the mnemonic was NOT password protected, but I cannot find anywhere how to do this with a password. Password protection of the mnemonic is essential when using the Trezor, and to have password protection is also an essential part of BIP39. But how do I do this?

Thanks!