did a search for programming software and found a post on radioreference by " siren134" who stated "Does anyone know how to change the serial number on the ht1250. I have programing software. ....." Frank KD4CAW
The easiest way is just to call your local radio dealer and ask since the ht1250 is a newer model. You could also just search on eBay. The software is not cheap though.
Please just take the radio to a 2 way dealer or a Motorola service shop. If you ask for software ot a copy of software us Motorola people look at you funny :)