You can delete a contact from a trip by following these steps!
1. Go to the trip you want to remove the contact from
2. Click on ...More
The button will be in the top-left corner of the itinerary, to the right of Settings.
3. Click on People
4. Remove the Contact
Simply click on the red circle on the right-hand side of the contact, and it will remove them from the trip!
Important Note: If you remove a Contact from a trip that is Private and has tagging, they can still view it if they leave the trip open, but they won't be able to see updates to the trip or use the group chat feature.