The author of the article successfully modified Grafana's source code to enable a specific feature, specifically the "Logs for this span" button in the Trace visualization. The modification involved adding two new data sources, InfluxDB and FlightSQL, to the list of supported log input sources. To achieve this, the author added these data sources to the `TraceToLogsSettings.tsx` file and created a custom query function for each data source. The author also modified the `createSpanLink.tsx` file to include the new queries. After making the changes, the author built a Docker image of Grafana with the modifications and tested the results, which included enabling the "Logs for this span" button and adding a log link next to each span. The article aims to inspire developers to explore and adapt open-source projects to their needs, rather than simply using existing features without modification.