1. First step, make a github.com account.

2. Find the asl script you want to update. (This should be listed in Resources here on src).

3. Click on the edit pencil seen here:

4. Add your desired changes and click Commit Changes.

5. Now travel to the Pull Request tab and click "New pull request"

6. Click "Create pull request" to send your changes to the owner for review.

In the event a script owner leaves the community, upload your script to your own github account. Copy a link to the raw file and make a pull request of the autosplitters code, placing your raw link where the former script owner's used to be.

https://github.com/LiveSplit/LiveSplit.AutoSplitters/blob/master/LiveSplit.AutoSplitters.xml