If you have a Win PC, use Paint, free software that comes on the system. Open the file in paint, and click "view", zoom out, and you
can easily crop -- DO NOT SAVE OVER YOUR ORIGINAL FILE! Use "save as" and modify the name.
And use "resize" and set to about 800 or 1000 pixels max dimension, and again, DO NOT SAVE OVER YOUR ORIGINAL FILE!
I save as original name with a "crop" or "small" added just before the end of the file name.
Bill