Define "Change our genetic code" the virus integrates itself into our genome yeah. You could maybe use CRISPR to edit out some important genes from HepB, but even that would be exceedingly difficult. The virus is both in the genome and also existing on its own in its packaged form. It infects a lot of cells, and you would need to remove it from all of them, or it could just re-infect again. Delivery of CRISPR to cells is still difficult, and I am not sold on it being used in a drug like capacity as of yet. Maybe in the future?
RE: Better Understanding The Workings Of Hepatitis B With A Transgenic Virus