Open either the "Bookings" tab (through the navigation top bar), or the "View bookings" tab of any of your events.

Find the participant you want to edit. You can use the search box on the startlist to find it quicker, if needed.

Once you've located the participant, click on their Booking ID (pointed out below).

This will open the participant edit screen. You'll be able to see all the participants who were part of the booking on this screen. Go ahead and click 'edit' on the participant you want to update.

You'll now be able to see the booking fields for the participant. Make your changes to whichever field(s) you need to.

Once you're happy, scroll to the bottom of the page and click "Update".

You'll see a "Booking information successfully updated" message. You can now close the Edit booking info window, and return to your dash.

To edit more participants (whether in the same booking, or different), just repeat the steps above.