My name is XXXXX XXXXX I am an experienced criminal lawyer.
Unfortunately, I don't have very good news for you. Pennsylvania is one of the strictest states when it comes to removing something from your record. They will only expunge summary offenses. Other convictions cannot be removed from your record for quite some time.
In order to get it expunged yin Pennsylvania, you have to be over 70 years old and have remained out of trouble for ten years following the completion of your sentence, or it can be expunged three years after your death. Neither prospect will do you much good now.
Another remedy -- which would not erase the record -- would be to see if the governor of the PA would grant you a pardon. These are very difficult to obtain, but they do get granted every now and again. You could apply for it by yourself and at least not have to incur the expense of a lawyer. You would need the official form from the Pennsylvania Board of Pardons in Harrisburgh. Here's a link to a sample form
so that you can see the work it will entail.
The only other option is also a longshot. That is is to retain a lawyer to reopen your case and petition the judge to have the matter dismissed in the interest of justice.
This would not be supported by the penal and procedural laws in your state and also the petition would have to come before the very same judge who presided over your trial, so it may be a longer than longshot. However, a judge always has power under Equity to grant a petition like that even when the law doesn't provide for it, if it is necessary to prevent an injustice from occurring.
So with a particulary compelling argument, if the judge is willing to hear the petition in the first place, it could happen for you.
Courts are sparing in their use of the equity power and many judges will not touch this at all, but it is something you could explore with a local criminal lawyer who would be able to tell you how viable this would be with your particular judge and whether it would be worth the money you'd have to lay out to get it done.
I wish you luck.