Reverse Sorting with IComparable

If your User class can be changed to sort in reverse order, you can try other answers which suggests modifying CompareTo method. Otherwise try the following.

users.Sort();//Sort normally
users.Sort((x, y) => y.CompareTo(x));//Reverse sort

If you want to reverse the order, just reverse the comparison:

public int CompareTo(User b)
{
    return b.total.CompareTo(this.total);
}