Once one is baptized, it cannot be undone and that is for the good of the individual who, no matter what struggles they may be going through, remains a part of the Body of Christ.
You can't get unconfirmed either. I believe my colleague Eric answered a previous question related to this that should address your questions.
There are similar issues you can read below.
- Is there a reason behind your desire to do this?
- Can we help clarify an issue or address a pastoral concern?