1. Select the image and click on the Editor icon

2. Change the dimensions of the image using the Image scale scrub bar OR by entering dimensions in the Image width/height fields  
3. Set the cropping dimensions by dragging the crop box over the image OR setting the dimensions in the Crop width/height fields. Select Apply to commit the changes
4. This will return you to the main editor screen where you will be advised of the new file name. Select 'Apply'
5. Save the change in the Editor.