[Dano]

Open your Saved photo on your desktop....right upper corner will be 3 dots, click to open.....click "resize".....resave the resized photo into your file. This pic will be resized small enough to be excepted on your post.

Then of course you will have to follow the instructions that are below your post window. Click "Manage posts" This will open another window where you can click "browse" ,your photo file can be imported from where ever you have them saved.

Just follow the prompts