First, follow this link: https://forums.totalwar.org/vb/local....php?catid=193

Then, click "add entry". Enter the name of your file in the line that is labeled name. Far below that, there is a line labeled "upload file". Click browse and upload your file. Then click the submit button.

In the next screen (the one you got after following the link above), right click on the link to your file. Select "copy link location". That is the link that you will post.