Connor,
If you are using a PC with any microsoft OS you should have a program called "paint". Right click on your picture file and select "open with". Choose "paint" from the options. On the top menu click on "image" and "stretch/skew". There will be two boxes with "100" in them. Change the "100" to "75" (this is based on your file size of 117kb) in both boxes and select "OK". Then save the file as a ".jpg". It should be around 85~90kb.
From the "reply to post" box on the forum, look for the green camera icon below the reply box and click on it. Choose browse from the pop-up menu and find the file you just resized. Select it and choose "OK". You will now see a string within your post. You will need to delete everything before "http" and everything after ".jpg". There's one more step ... highlight the whole string and go to the top of the post box and select the fourth box from the end "insert image". This will bracket the string with [img] and make it visible in your post.
It may sound complicated, but once you've done it you'll see how easy it actually is. Good luck.
