We can't give specific legal advice here and that is what you are asking.
The local court house may have a self-help section. Check into the possibility. The other possibility is to sweat talk a court clerk into showing you an example from a case in progress. The whole purpose here is to "remove" the conviction, so you are not likely to be able to see a case in which the request was granted. But, the info may still be public if a case is in progress.
If you originally were represented by an attorney or public defender, you might determine if their representation actually covers this one or if a separate charge would apply, in the case of a private attorney. Call up and ask or review your retainer agreement, if you originally had private counsel. Nothing ventured, nothing gained. If you are told no in the case of a public defender or that a separate charge applies, you are no worse off than you are right now.
This one actually does seem rather routine. You might get quoted a flat fee for preparation and filing of the documentation needed. It could wind up not costing that much. As with most things, it may pay to shop around, if the the price you are initially quoted seems too high. Stick with criminal defense law firms as they probably have sofware programs that may allow them to crank out much of what is needed without too much time and effort spent on attorney review.
If it were me, getting this final step done correctly would be more than enough incentive for me to have an attorney do it, even though it seems fairly routine. After all, this is "the prize" you were seeking when your attorney originally got you this "plea bargain". I would not let a few hundred dollars stand in the way.