Buying Already Occupied Building

[Tom Scott]

I'm looking at a few 4-plex buildings and most already have long term tenants. I know I need to look at the lease agreements before I buy, but what else do you do in order ensure an easy transition for the tenant? How are the tenants various security deposits usually handled as ownership transitions? How do you handle migrating the tenants over to the new payment system (if applicable)? What else should one look out for when buying an occupied building? 

Tom