You can change your contact information (i.e. address, email) on your profile by logging onto the national Mensa website here: http://www.us.mensa.org/
Then go to “My Mensa” and select “My Membership Profile” from the dropdown list.
Then enter your email and password.
Once you’re logged in, you’ll see on the left side of the screen a box that lists your address. If you click the button that says “Edit Contact Info” below that, you’ll then see a list of all your contact information. Under “My Addresses” click “edit” next to the address you want to change.
A window will pop up where you can modify your address. Change the information, and then click the blue “save” button at the bottom of the window to change your address.