SQL Upgrade question

I've got a brand new upload of Zen 1.3 but have uploaded it with my old database. I previously installed the UK Mod and would like to install it again as it was the most brilliant piece of work which I was most grateful for.

This time though I'm concerned that the SQL changes I previously made to the database may hinder the upload of the new SQL changes.

I don't understand phpmyadmin and the thought of modifying my tables manually terrifies me - can I simply upload the new changes on top or is there an "uninstall" for the old ones?  Ideally I'd install your 0.8 mod but suspect the 0.4 is more closely matched to the 1.2 changes.

What's the best way forward?