I have a room including some users. I want to remove an specific user from the room.

Here are my Models:

```
public class RoomModel
{
    [Required]
    public int Id { get; set; }
    public string Name { get; set; }
    public string Admin { get; set; }
    public ICollection<UserModel> Users { get; set; }
}

public class UserModel
{
    [Key]
    public string UserID { get; set; }
    public string UserName { get; set; }
}

```

And my database context:

```
 public class DBContext :  IdentityDbContext
    {

        public DBContext() 
        {

        }

        public DBContext(DbContextOptions<DBContext> options) : base(options)
        {

        }

        public DbSet<RoomModel> Rooms { get; set; }
        public DbSet<UserModel> Users { get; set; }
 }

```

How can I remove an specific user from the room and save changes in database?