what i understood is that he needs to invert the input . 0 in> 5 out, 1 in > 4 out, 2 in> 3 out, 3 in> 2 out, 4in> 1 out and 5 in> 0 out.
at zero input this circiut puts out five volt. i'm sorry , i should have noted that the output is at the collector of the transistor. the problem is that at 5 volt input , the output only drops to approx 0.8 v. this can be circomvented by decreasing the base resistor and choosing a high gain transistor. but this will also have an effect on the signal that is driving this circiut. remember that the input impedence of this circiut is bassically the base resistor.