Simply open an Issue with the most amount of details:
- Mono/.NET version
- Project/file version
- Environment (OS, Window Manager, etc.)
- Explain what you were doing
- Do a screenshot whenever possible
You'll have to explain:
- Why are you requesting a pull? (New feature? Bug fix?)
- What does the pull affects? (Animation engine?)
- Your code.
- If your code is terrible, I'll tell you to
See the Translations Wiki page.