Elevator Modernization Anyone?

[Christine I.]

I have 3 elevators in 3 buildings, built in the 1970’s. Each building is 2 levels with 10 apartments on the second floors. We have owned these for quite a few years and I plan to continue ownership. I’m in California. Anyone had any experience doing an upgrade such as this?
I’ve got one bid and in the process of getting a second. It sounds like they will be similar. Have a question in to an attorney of what my legal obligations are to upstairs tenants. 
If you have any experience I would love to hear about it.