Pull Request Guidance

I just modified Forge to allow a modder to add custom tabs to the creative menu. The system works flawlessly as far as I can tell (yes, I tested it...). The modder just has to declare an instance of CreativeTabs with the index and name they want, then add a localized name similar to how you add names to Blocks and Items. The tab then shows up in creative mode and the modder can use Item.setCreativeTab(theirNewTab) to categorize their new items and blocks. One problem: I have no clue how to set up a pull request. Yes, I just modified the entire creative inventory system but I can't figure out pull requests. This is slightly embarassing  . Can somebody give me a push in the right direction (or maybe a pull? ) on how to set up and submit a pull request with my new code changes? Thanks!