The operating agreement could be amended for a new partner.

Do you create an amendment to the original lease to add the extra adult?

If said person were to join an LLC by amending operating agreement to establish ownership or a decent amount of ownership of an  LLC that has ownership of 393 units bought 20 years ago would the experience of that ownership be transferred to the member that has just joined?

You can still share other buyers offers with everyone who submit offers if you'd like to see if anyone will amend their existing offer later if you think you have a strong enough property in higher demand.

Finally digging through the dol.gov, found a helpful link: http://www.dol.wa.gov/business/realestate/assistants.htmlI see that you don't need a license if you are:Property management assistantsUnlicensed assistants who provide property management brokerage services for the owner, designated broker, or managing broker may perform the following tasks and duties:Unlicensed assistants may… Deliver lease applications, leases, or any amendments.Receive lease applications, leases, amendments, security deposits, rental payments, or any related payment for delivery to, and made payable to, the owner or real estate firm.Show rental units.Execute leases or rental agreements, rental payments, or any related payment for delivery to, and made payable to, the owner or real estate firm.Act as a scrivener, completing blanks on preprinted and preapproved rental agreements with the exact language provided by the property owner, designated broker, or managing broker.

thank you all @Steven Hamilton II and @James Syed for the replies...looks like I need to go back and amend last years return and get an extension for this year.

@Carl Carlson Never too late to make amends.  

And God no I do not wanna file income tax amendments just to fool the bank, Can honest people find finance in the world today??

Another way is to get the actual costs, amend the agreed sale price, the note is 100% and the seller shows up with settlement costs, but the title folks need to know that as it effects settlement expenses.

Unfortunately I already filed my taxes, and my accountany doesn't recommend amending them.