To edit an instant video and convert from MP4 to RMVB file in Corel VideoStudio Pro X5, follow these steps:
1. Import your MP4 video into the software.
2. Drag and drop the video onto the timeline.
3. Edit the video as desired.
4. Go to the "Export" tab and choose "Video File" as the output format.
5. Select the RMVB format from the drop-down menu.
6. Click on "Export" to save the edited video as a RMVB file.
