You can manually add or remove contacts from a segment at any time. Click here to learn more about manually adding contacts to a segment.
To remove contacts from a segment, locate them in the segment and check the box to the left of the contact's email address. If you are looking to remove multiple contacts, check the boxes for all that apply. Once you have selected the contact(s) you'd like to remove from the segment, click Remove Selected in the top-right.
*Note: This will only remove the contact from this particular segment. This will not remove the contact from your account as a whole.