You can easily change your information when you're signed into GovernorHub by clicking on your name at the top of the screen (your name will show where indicated by the green arrow below).

You will then need to click on the 'profile' option.

This takes you to your profile page, where you can change or fill in your Declarations of Interest by clicking on the second tab along, Declarations (you will notice there is a separate tab for Confirmations).

Here you can add a new declaration, confirm declarations are correct or download a copy of all existing declarations.