You should click on "Contributions", find this incorrect article, click the small button to the left of "Add resources" and select "Remove".

I had previously been able to do this as Pawel describes. However, this option was not available when I attempted to add an amended version myself last week. I got around this by clicking "contributions" then the drop down arrow to the right of "add resources". Once in the drop down menu select "add additional file" you can click the "x" icon of the offending file there to delete.

Go directly to your profile. Click on contributions, at the bottom you will see "Add resources" and click on "Remove" It will disappear as soon as you click.

Thank you.