Once you have an image open from within your Gallery, the vertical 3 dots at the top right should be tapped, and "Edit" selected.
Tool icons are shown above and below the image (if not visible, tap anywhere on the screen to make them appear). Hopefully at the bottom left you should see a circle containing a wrench icon, called the "Adjustment" feature. Tap it.
This should enable you to see the "Rotate", "Crop", and "Resize" tools; the Resize tool is the one you want to tap.
You should be able to either drag a corner handle to make it smaller, or better yet tap a percentage button along the bottom to reduce the size of the image. Keep in mind, though, that going too far may make your photo a bit less ideally resolved when it's finally posted on the Forum.
On regular camera-wrought pix on a computer, I commonly use Paint and select around 25% to reduce the data load to; it depends on the camera's original MB rendering, and each camera is different. As long as you can get it below 300kb, it should fly as far as attaching it to a Forum post. To determine a photo's kb load, back up out of the Edit program to your original photo pick and tap the 3 dots in its upper right corner again, but this time instead of tapping "Edit", select "More info", and hopefully down under "Details" should be its size.
Now admittedly, I don't have a smartphone and have been relegated to a waterproof, tough-as-a-rock flip/dumbphone. But I have to show my wife how to use her Samsung S5 all the time. Go figger. That said, I've not had to actually do the above procedure, but rather have summarized from a book I bought her, that amazingly enough it seems only I use very often. Go figger X2. It makes mention of a second image-selection feature called "Studio" or in this application, "Photo Studio", but I think the procedure via either route ends up essentially the same.
At any rate, perhaps you might give the above guidance a try, Bryan, and let us know how well it works. Then maybe Steve can edit the instructions with numbering or other pertinent or corrective managing (other phone brands may somewhat differ), and add them to our How To pdf.
-Joel
