1. Drag the Image into Time Line (note also shows how to make arrowhead in Photoshop incidentally)
2. Hit B to activate Blade tool hit-B, to get out of Blade hit-A (normal mode).
3. Hit A to get back into normal model and apple-X to cut the part you don’t want
4. Export to a file (on menu tab)
5. Export to a file (you can use compressor to make it smaller), or Color Balance (to make it better