Need Lending Advice for Refi

[Deep Patel]

Hey all! As a REI amateur, I need some advice/insight into how to go about my father's lending situation. In essence, our primary residence has a cosigner on the loan we are trying to remove. The principal is $253k-ish. Value of the home is estimated at $375-425k. In addition, we have a commercial loan (not a mortgage I am pretty sure), with a principal of $220k, that we used to purchase two investment properties. In total we have six investment properties (worth $125k each, or $750k total).

The main issue with refi I think will be his income. He took a hiatus from work for a few years and is now back to working. He opened up his own business and it is doing well, but it has just been a year. I do not know if banks will consider this income due to the length of the income. If they do, at even 50-70% of net income, we would be set. Is there a way around this with self-employed people? Does a guaranteed payment change anything? 

Also, how else can this problem be tackled? I was considering perhaps refi-ing and taking money out of the investment properties to free up capital and use it to pay down the residence mortgage and hopefully he can get approved then. I am very, very new to this but he has little understanding of the language or real estate, so I am trying to help him navigate through all this. We just got the six properties last year through a 1031, so if I could do that, I am hopeful about this! Thanks in advance to the BP community! You all have already helped my family so much.