You can change the password on your Yacht Week account from your account page.
Go to your account.
Press "Change password" in the left-hand menu.
Enter your current password, then your new password, then confirm the new password.
Press "Save", and keep your new password somewhere safe.
Note: this password is only for signing in to your account on theyachtweek.com. The Yacht Week app uses a different sign-in method — a 6-digit code sent to your email - so this password isn't needed there.