A person's probation can potentially be terminated early in Pennsylvania, but it will depend. As a rule of thumb, a person should wait until at least the halfway mark of their term of probation before they considering making such a request. Having the support of the probation officer will of course help. In some instances, the probation officer may support the person's request to have their probation terminated early.
In terms of most effective steps to address trying to get your probation terminated early, it would require efforts to be taken to try to negotiate the agreement of the applicable district attorney's office. The district attorney's office not to be defeatist, but often at best, they would defer to the court, if not, altogether object to the request, district attorney's office for policy reasons may in many instances, look upon the matter as it being a contract between the defendant and the court in terms of the original sentence and it should not be changed just as say, the district attorney's office does not go in at the end of the sentence to try to have probation extended, they can make the argument that the defendant should not try to have the probation terminated early.
That being said, if there's circumstances that would or could convince a judge to allow probation to be terminated early, either say, employment or family obligations, school obligations, any positive information and documentation that can support the request that should be leveraged, both with respect to the district attorney's office and as needed, ultimately the judge to make the request.
So there's a number of steps that have to be taken. An experienced Pennsylvania criminal defense attorney will help you best understand how to try to get your probation terminated early. They should be involved from as early as possible in the process.