Project > Project Members > #project member
The Administrator can remove the name of the individual from the Project and assign a new Project Administrator to this role.

or
Account > Members > Project

To add a new person to the Project, you can do so from either of these two areas.
Project > Project Members > 3project member > +Invite Account/Project Member
Account > Members > Account/Project > +Invite Account/Project Member
Click the drop-down arrow and choose which role the new member will have.