If I ask for a trial, and then just change my mind, can I do it by mail before the court date? Or do I now have to show up at court on the day of the trial? Or is there a procedure to go in before the trial date, and say I changed my mind, and plead guilty?

Thanks

You can just show up on your regular court date. They'll offer plea deals to everyone who shows up. If there's no more wiggle room on your charge for a reduction, you can just plead guilty to whatever is on your ticket.

Also if you can't make the court date yourself you can always send someone else to represent you. It doesn't have to be a lawyer or paralegal it can be anyone of your choosing.