The reskin file is explained in several of my Navcore installer threads.
Since you already found it the systax is quite clear:
The first two entries are identical, this is to tell the TT which one is active.
So you remove one slf-Self; and replace it with for example two fow X50:
37-GO x50;37-GO x50;slf-Self;17-Rider;34-ONE;35-XL;36-XL LIVE;37-GO x50;39-Start;18-GO x20;25-GO x30;24-GO x40
When you start after that you are in the X50 emu ;)

Thanks for the explanation but ive decided to give up on the voice problem, its just a bit too complicated for me,

Thanks again for all your help

Pete