Legal Question in Criminal Law in California

"I plead to a felony vandalisim. I wasn't guilty. ..It's been 6 months"

Then you should not have pled guilty.

You obviously told the judge on the record at sentencing that you did what you were accused of, and were 'guilty as charged', or he would not have accepted your plea deal. That was the time for you to assert your 'innocence' instead of pleading guilty, not six months later after you find felony probation harsh. If you wanted to 'prove your innocence' you could have demanded to go to trial instead of pleading guilty.

"Being that I'm innocent does that make the probation illegal"?

Really? You are the only one 'knowing' you are 'innocent'. You told the court you were guilty, and are simply suffering the normal 'legal' probation consequence of that plea.

" I need to correct this "

Now, six months later, you are going to have to bring an appropriate Motion to Set Aside your plea, based upon some valid 'legal good cause', and supported by admissible credible evidence and/or witness testimony, plus pertinent case law citation, and convincing legal arguments. Just saying 'I'm innocent' is not a convincing legal argument because it means either that you lied to the court at sentencing, or you are lying now. And, saying you were 'forced' or 'pressured' to plead guilty is also not a credible legal argument, because the judge asked you on the record at sentencing if you were doing your plea 'voluntarily' without pressure.

Since you waited six months to complain, you have probably passed any statutory time limits for bringing any other Motions or appeal of your conviction, even if you had any grounds for appeal - meaning the record will show that the judge made some substantial legal errors of law or facts in the case and sentencing. You haven't mentioned any, and the judge was not involved in the case outcome until you presented him your plea deal at sentencing.

If you. think you can somehow comply with or overcome all those issues, you could try to hire a good criminal defense attorney to 'prepare and file such a Motion for you. The PD office will likely not be willing to do anything for you, as the case is over as far as the PD, DA and judge are concerned.