How risky is attempting to negotiate down loan balance on a sub2?

[Brian Kempler]

I'm reading "Get the Deed!" and the suggested strategy on underwater deals is to take it sub2 anyways, then try to negotiate down the loan principal balance and/or payment. Failing that, rent it on a long term lease option to wittle down the balance.

Do you guys believe loan acceleration risk goes up substantially by trying to negotiate down the debt as the new owner of the property? I'm not even sure the bank would talk to me in this instance -- the debt is still not mine. Maybe I'm missing a step. I don't think an Authorization to Release Information grants negotiation rights. Any guidance is welcome!