If you are running a Microsoft operating system (windows), it is likely that you already have Microsoft Photo Editor installed on your computer. Try searching your computer by entering "photo" in the filename search. If you have this program, or something similar, after you open your file click "resize" and then save your photo with a new name. Check the help menu to find out more about options for saving your files. The "quality factor" or "compression" will determine your file size. You need to experiment with this by saving the photo using different factors with different file names and then reopening the files. If you are posting here, you want to keep the file big enough to retain resolution, but no more than 700x700 pixels and a maximum of a 80kbyte file size. Use jpg format for saving pictures.