Having trouble proving a language is NP-complete

Question

I'm asked to prove that, if P=NP, that 0*1* is NP-complete, but I'm having trouble going about doing it. I know it's fairly easy to prove it's NP by creating a TM to verify an input (which can be done in O(n) time, and that's polynomial).

But then I now have to reduce an NP-complete problem to 0*1* in order to prove that 0*1* is NP-complete. I'm thinking reducing SAT to it, but I have no idea how to do that, since in SAT all you can use is and, or, and negate, and there's no way to tell if a 1 came before a 0 in an input by doing that (at least, as far as I can tell).

Thanks