Java Coder To Update Software and Package with Installer

Hello, I'm looking for an experienced Java coder to help me update an existing software and package it with an installer. I need someone who is well-versed in Java and has experience working on software updates. The goal is to modify the existing code and incorporate revisions to bring my software up to date. I also want to add another function from opensource java software that can be found at https://github.com/FOSStriangulator/FOSStriangulator
I have $400 to spend on this project.