In search of a method to resize these images, I found an easy way using Terminal.

• Open up your Terminal app (can open Spotlight and search terminal).
• cd into the desired image directory (e.g. if they are in your Pictures directory, you may: type "cd Pictures/").
• Enter "sips -Z 1500 *.jpg" (with no "" marks).
• Press enter. It will output every .jpg file in the directory you are in into a max of 1500 width or height.

• Change the "1500" to the max resolution you want.
• It keeps the aspect ratio (-Z is the command for keeping aspect ratio).
• Keep a back up of the full resolution images!