Legal Question in Criminal Law in California

You must file a motion to withdraw your plea before sentencing, including specific reasons the court should allow you to do it. Those reasons might include failure to advise you of immigration consequences or sex offender registration requirements, or the fact that you were suffering from a mental condition that affected your ability to understand what you were doing.

"I changed my mind," or "I think I could have waited for a better deal" are not acceptable reasons to withdraw a plea. Judges often use the term "buyer's remorse" when the reject a motion to withdraw a plea based on that sort of statement.

File the appropriate motion, and then face the wrath of the judge and DA who will be intent on taking you to trail and convicting you. There will be no further plea bargain offered if you do this.