How to update rental agreements for long term tenants?

[Jing Tagle]

I have 2 part question. First question is about old rental agreements.  I have several tenants that have been renters for over 10 years.  They're all on month-to-month and their rental agreement is somewhat outdated.  How do I update it or can I just have them sign a brand new one? Second question is about last months deposit increases.  If I increase rent every year, do I need to also increase the last month deposit or can I collect the difference during the last month before they move?