It will be likely the bank will want proof of income and tax returns and a letter of explanation.

@Christopher OlsenSince your dad didn't have a will you and your brother could file as co-administrators of his estate (Notice of Petition to Administer Estate) and petition the court for Letters of Administration.This will give both of you legal authority to sell the property and by even hiring an eviction attorney or you both can continue to own it.You both have a legal interest in the property but mot ownership (Yet).My feeling is this tenant may try to file for Adverse Possession (Cal.

Can you fellow landlords share the Past Due Letters that you are sending to your tenants during this time. 

1) I have seen people get loans with just an offer letter, this is usually with like a first time buyer program and usually those are not available for multi-families.

@Phil Kerb I might start by hiring a lawyer to write a letter telling the neighbors to remove their stuff.

Any advice on the language or a letter I can use to reach out to the cosigner?

Accreditation is achieved by either proving the investor has a net worth of $1,000,000 not including primary residence; by proving that the investor has made $200,000 a year over the past 2 years, with a reasonable prediction to make that again this year; or by a letter of accreditation by a CPA, attorney, or other professional.

Which would be a matter of having your father write a brief letter, which should not impact your loan at all.

She just received a letter from them, 71 days after stating that they are not only keeping the deposit, but she owes them money.

I just received a letter from the city stating that the property has appraised for $177,00.