How do I downgrade my felony charge to a misdemeanor after completion of my parole?

Review the following:

California Penal Code 17.(b) When a crime is punishable, in the discretion of the court, by
imprisonment in the state prison or by fine or imprisonment in the
county jail, it is a misdemeanor for all purposes under the following
circumstances:
   (1) After a judgment imposing a punishment other than imprisonment
in the state prison.
   (2) When the court, upon committing the defendant to the Youth
Authority, designates the offense to be a misdemeanor.
   (3) When the court grants probation to a defendant without
imposition of sentence and at the time of granting probation, or on
application of the defendant or probation officer thereafter, the
court declares the offense to be a misdemeanor.
   (4) When the prosecuting attorney files in a court having
jurisdiction over misdemeanor offenses a complaint specifying that
the offense is a misdemeanor, unless the defendant at the time of his
or her arraignment or plea objects to the offense being made a
misdemeanor, in which event the complaint shall be amended to charge
the felony and the case shall proceed on the felony complaint.
   (5) When, at or before the preliminary examination or prior to
filing an order pursuant to Section 872, the magistrate determines
that the offense is a misdemeanor, in which event the case shall
proceed as if the defendant had been arraigned on a misdemeanor
complaint.

http://www.uscis.gov/err/L2%20-%20Legalization%20Application%20for%20Adjustment%20to%20Permanent%20Resident%20Status/Decisions_Issued_in_2006/Jul122006_01L2245.pdf

http://www.law.cornell.edu/supct/html/01-6978.ZO.html

http://74.125.47.132/search?q=cache:QvO1U5BpwsgJ:www.usdoj.gov/osg/briefs/2006/0responses/2006-0432.resp.html+california+downgrade+felony+conviction+to+misdemeanor&cd=4&hl=en&ct=clnk&gl=us