To edit an instant video and convert from MP4 to Matroska file in Corel VideoStudio Pro X5, follow these steps:
- Import the MP4 video into the software.
- Drag and drop the video onto the timeline.
- Click on the Export button.
- Choose "Matroska" as the output file format.
- Adjust the export settings as desired.
- Click on the "Start Export" button to export the video as a Matroska file.