You have to sign your IPA file with a certificate generated against the UDID. Apple does not make things easy. This is why I have ultimately made the decision to not support them going forward into the future.
Anyways, you have to add the UDID into your developer account portal and generate a new cert with that new UDID, and all the other existing ones against it.
Then recompile with that cert. You may be able to simply re-sign with that cert, but I am not sure how. its easier just to open the project and recompile it.
Thats all you can do.