My middle name is Jr. but i want to change it to Jay.
It's not expensive, I believe the filing fee may be around $150.00. The Court Clerk's office in your county should have the forms you need to do this. You likely will not need an attorney, but you will need to show up when the judge schedules a hearing for you.
The answer given does not imply that an attorney-client relationship has been established and your best course of action is to have legal representation in this matter.