Execute File before Actions appply

Hello guys, I've a big problem here with one of our updates!

We've a service wich is part of the update which isn't stoppable (due to a bug in the latest update). I've therefore added an updatehelper which simply kills the service. The problem now is, that the Action "stopservice" is executed before my helper runs. If I remove the action, the update will quit due to it can't kill the service

Any ideas here?