Add/Remove many to many associations in Entity Framework
It should look something like this:
To Remove Relationship
user.Roles.Remove(existingRoleEntity);
To Add Relationship
user.Roles.Add(existingRoleEntity);
You can use the navigation properties on the entities:
(assuming u is a User object):
using (var db = new UserEntities())
{
Role roleToRemove = db.Roles.Single(SelectRoleHere);
User user = db.Users.Single(SelectUserHere);
user.Roles.Remove(roleToRemove);
db.SaveChanges();
}
EDIT - Added SaveChanges based on Slauma's comment.