External mic for Go 520?

[Britphil]

The Go 520 doesn't have an external mic socket and the internal mic quality is pretty poor when I use it. I would like to try hardwiring a mic socket on a trailing lead in parallel to the internal mic so I can use an external mic. Any views on whether this might work, or indeed on how to dismantle a 520 (I have seen a guide to dismantling a different tt model but this one has so far defeated me - I have removed the two visible screws but it seems determined not to come apart!). I realise this would invalidate the warranty (or I may totally break my tt) but I am happy to take that chance.