How much would it cost to get an animal cruelty charge expunged?
You have to petition the court to reinstate your license. It is a complicated process and there is no guarantee of success. You should consider contacting an experienced DUI/DWI attorney.
You would have to talk to a DWI attorney practicing in Nevada to answer that question. I would say very unlikely given that there is a minimum 30 days by statute for persistent offenders. However, a skilled DWI attorney can possibly get that charged reduced.
An attorney can get this evidence for you and use it much more effectively. A motion to preserve evidence is relatively simple, but there are still a lot of mistakes you could make if you try to do this alone.