They say it is easy. but us old dogs still have a hard time
On the left lower corner of your screen you see reply. It will take you to your post, You make your statement then at the bottom of the screen you see click to upload. It will show upload pattern then it takes you to your pics and you pick the ones you want to upload.
You can practice this on the forums test area You can see where it leads you all through the process.
Larry