Brown Line to Green Line

Where and how can I transfer from the Brown Line to the Green Line without exiting and re-entering the terminal?

I’ll enter the Brown Line at Kimball shortly before 7:00 AM on a weekday.  I know I can stay on the train and avoid the 7-9 AM bike-on-trains prohibition.  I’ll be taking the Green Line to the Cottage Grove terminal.

There are two stops downtown to transfer.  Do both have elevators to transfer between the trains?  Do they both work going back north when I return?

Any help or advice would be appreciated.