Can you request a new judge? What has to be done to do so?

NO, you can't just ask for a new judge. If that were an option, defendants would ALWAYS ask for the most lenient judges. The FIRST step would be for your lawyer to request the current judge recuse themself. If the judge refuses, and there is CLEAR evidence of bias, it is possible to request the judge be removed. if your lawyer has not already brought this up, you probably don't have actual cause to make the request.