2. Enter your Stellar account ID.
3. Enter your Bitcoin address. For P2SH (multisig) addresses, you will be asked for a redeem script.
4. Sign a displayed message. For P2PKH (normal bitcoin address) only one signature is required. For P2SH (multisig) addresses you need to provide as many signatures as required to release the funds from a P2SH address.
5. If signatures are correct, lumens will be sent to your Stellar account.
Not quite sure exactly what sort of redeem script they require, or how you go about generating it... and getting 2 sigs using a 2FA wallet would require you to ask TrustedCoin for help or to restore your 2FA wallet using your seed which apparently puts 2 of the 3 keys on your computer... see: http://docs.electrum.org/en/latest/2fa.html
Pay attention to the note at the bottom tho:
Hi HCP,
Could you please confirm if I restore my 2FA wallet using seed, could I sign the 2 of 3 '1' start address and claim the XLM?
Thanks