To delete a member entirely, you must be the Account Owner or an Administrator in your place. For information on specific roles and their permissions, check out the article User Roles and Permissions.

Delete a Member 

1. Go to Members, then search for the member you wish to delete. 
2. Click the Trashcan Icon to the right of that member's name and the member will be removed from the place.

Delete a Share

*Important* - To delete a share, you must be an Administrator within your place.

1. Go to Members, then search/select the member you wish to delete. 
2. Scroll down to the bottom where it says Memberships. 
3. Click the Trashcan Icon to the right of the group you wish to remove from the member and the share will be deleted.