Legal Question in Criminal Law in Michigan

I'm not clear on what you signed. The important event would be the plea hearing in front of the judge: you either plead guilty or no contest, or did not. Some courts have defendants sign an advice of rights document but that's just doing something on paper so the judge doesn't have to verbalize the same information to the defendant (like: you're giving up your right to a trial by jury, you're giving up your right to confront witnesses, etc.). Short of that, "signing a plea agreement" does not cross a line that you can't retreat to. But, if you actually entered a guilty or no contest plea, then there may be legal barriers to you withdrawing your plea. The court rules say that a judge should liberally allow people to withdraw pleas before sentencing, especially if they are doing so because they claim they are not actually guilty; this is not an absolute rule, though, and there are some situations where judges would not or should not allow the plea to be withdrawn (like if it's being done because the defendant got a preview of the likely sentence and is trying to withdraw the plea because they don't like that sentence). It's even tougher to withdraw a plea after the sentencing hearing is over, and if that has happened you need to talk to a defense attorney personally about your options and whether your reasons justify such a request.