I am attempting to modify the audio files an NPC uses, I am currently stuck at the point where you click "select sound" and it brings up a list of forms. I have no idea where to go from here to find dialogue sound files, any help would be greatly appreciated

Assuming the speech is part of a Quest

In Object Window ... Quest > Where-ever the Quest in question is in the categories ... Double Click the Quest. Select Dialogue Views Tab

Find the text of the speech and double-click it.

In the "Responses" list double click on the approproate response.

Audio is half way down the form ...

its just after that point that i am stuck, in the audio section i cannot figure out how to assign it a new file, instead of the one it is currently using

In Audio > Sound Descriptor

Either right-click the list and do NEW, or edit an existing (depends what you want to do)

Then back to where you were before ^^^ and do Select Sound ... The list is all of the Descriptors

as far as i can tell that list only includes sound effects, I'm attempting to work with dialogue, specifically using some dialogue already in the game in a different part of the game, but i can't get it to work. For a custom NPC I'm making i want him to use "MGRitual03_MGRitual03Dremo_000DB368_1" instead of "HirelingQu_HirelingQuestTo_000BDFB1_1" when you hire him

Is this what you want to do?

http://www.gamesas.com/topic/1346483-voice-acting/