You can edit your followers fairly simply. First, go to Settings and choose Profile in the Zwift Mobile Link. Once in your profile, click on 'Followers."
Click on the icon to the right of the follower you wish to Manage.
And from there, the management menu pops up.
FYI: the only way to block someone from following you at the moment is to make your account 'Private.' We hope to include an individual block very soon.