Hi Cathal! Welcome to CPDL and thank you for sharing your edition with us. I have just finished posting the work; you were doing everything right; the last step was to click on the red link created at Anonymous and paste the code you received via email into the new page that would open. All the best, —Carlos (talk) 19:06, 24 May 2013 (UTC)
Hi Cathal, this is how to upload a newer version of a file: click on the "contributions" link on the top right of your screen and you will see, among other things, the files you have uploaded recently. Click on the file name you wish to update, and in the page that will open you'll see the option "Upload a new version of this file", just below the File history. Click on this link, select the new file on your computer and upload it; it's that simple :) Just take care not to change the "Destination filename" info. There's no need to change anything on your composer page. If you prefer, you can add to the works page (in the "Edition notes:" field) something like "Revision 2013-05-29. Corrected X and Y".
Regards, —Carlos (talk) 01:33, 30 May 2013 (UTC)