Do you mean you want to get rid of the bounty?
Well, there are a few things you can do... Choose one:
A. Exit the region you killed the guards in, and come back immediately. Then look for a guard. The options like "Resist Arrest" should appear. Choose to pay for the bounty (If you have the gold) or do Community Service, where you must do a job and accumulate enough gold to pay for the bounty. If you choose Community Service, you will be stuck making pies or something for a loooooong time...
B. Exit the region and spend your time somewhere else. Don't come back to that region for a long while (I'm not sure how long you should wait... maybe half an hour?). Then go back to that region. The guards would have forgotten your crimes, if you waited long enough.