[TW1] Altering buy and sell rates

[Basnap]

[TW1] Altering buy and sell rates

http://witcher.wikia.com/wiki/Shop_buy_rate_mod

The buy rates are governed by the

\DATA\2DA00.BIF\shoptypes.2da

file.

However, that one is a file for me, so how can I open only that specific table? I tried to edit the file with notepad from windows and notepad++, but it looks like I just jeopardized the file to a non-working status.
So, I need to open a .2da file, which I cannot find because I got a parent file, basically, and not a parent folder.

So, any advice?

Bonus points for explaining me how to install this TW2 mod:
http://redkit.cdprojektred.com/index.php?c=mod&m=show&p=114

Maybe there are some invalid values for the buy and sell rates, wild guessß Such as max 1 or 2 decimals after comma?

Thx in advance!