Using Kotor Tool, open:
BIFS | 2da.bif | 2D Array | creaturespeed.2da
In the very first row,
PC_Movement, you can modify the
walkrate and
runrate.
When you happy with the values, type a Control-s or use the menu to save as a "2DA v2.b" file (not XML). Save the file in the
override folder in your SW:KotOR application folder. These new settings will be used in place of the built-in defaults.
If you later want to adjust the values, open the
creaturespeed.2da file in the override folder from Kotor Tool's File menu (
File | Open 2DA File editor ), then edt and save as before.
Good Luck!
P.S. you can get Kotor Tool here:
Kotor Tool site