Either create a new thread or visit a thread where you want to attach an image. If going to an existing thread then click the "Reply" button (you can't use "Quick Reply" because you won't find the necessary button there).
1. On the posting page, you'll find a button "Add Attachment".
2. This window will open. Click "Add files" and choose up to 5 (!!) images from your computer.
3. Once all the pictures are loaded, your window looks like this (actually we would prefer for you not to use such big images as I have them here as we have limited space for attachments).
4. Click "Insert" to attach your pictures into your post. You can add text, insert pic #1, add text, insert pic #2 etc. if you want to. You can also delete attachments in this window. The button "Edit attachments" takes you back to the overview.
5.You can also resize your pictures after inserting them. Just click the picture and drag to the requested size.