Members - How to change Email Address

[Jaxon Justice]

I need to change the email address for a member on a board.

[Tayyab Bashir]

By changing the email address for a member do you mean changing the email address of another user on Trello? 
If that, then only that person can change their email by going to https://trello.com/username/account

(or if you have their credentials then you can do that yourself) 

But if you need to change the team member on the board, then just beside the Board name there would be an option for that.