It depends on your User profile. As a User, you can not remove yourself from a project.
A Super Admin or Project Admin can remove a user by following these given steps.
- Locate the given project in the list and click on Settings
- Click on Manage Users tab
- Find User in project users list and click on Remove
- A confirmation pop-up will appear. Click on Remove.
- User is removed from project successfully
Removing a user from a project will make the project contents inaccessible to the user. Project Items assigned to this user remain intact.