You can update the email address linked to your Bricklane account from the Settings page of your dashboard.
You can type over the existing email address to enter the new one that you want to use.
Once you have entered your new email address, please go down to the section titled 'Verify', enter your password, and click 'Save changes' to confirm the change.
You will then see the green bar turn a darker shade of green, and read 'Saving...' for a couple of seconds whilst the change is made.
You will then see a dark grey bar at the top of the page, confirming that the changes have been saved.