Screen replacement gone wrong, need some advice on what to do now.

Ripping the volume/lock ribbon is a very common issue to run into on your first go round. I am not aware of any guides for that but it is kind of a pain, especially if you have never taken an iPod apart. You have to unsolder the 4 points that connect the ribbon to the board (there is a good picture on the teardown guide on step 10).

The proper way to do it is to remove the logic board because the ribbon runs under a part of it. You can get away with running in under the board but it is not easy. If you look at the teardown guide until step 15 it shows you how to take everything out. The tricky part for some novice solderers is reattaching it because you have to make sure you have 4 separate solder points, none of them can be touching or else you will have a problem.

IMO I do not think it is worth the time,

Make sure you have the metal clip attached to the screen over the ambient light sensor (hold the screen up to the light and you will see the dot). Then when you are ready to seal her up push in the digitizer ribbon so it folds on itself and rather than pushing the screen straight down try to hook in the metal bracket in sort of sliding motion. If you mess it up and want to try and reset it just heat it up and you will be able to remove the screen without damaging the LCD. Hope that helps and let me know if you need any clarification