foot pedal as shift button

yo guys i recently bought an oxygen 25 n was wanting to use a foot pedal as a shift button but i dont know how to map it in traktor for shit hahaa

Just assign it as you would any other button.

I think you'd want to set it up so that in traktor controller mappings when you press it, it changes the value of a modifier. (off the top of my head) Add modifier 1, when m=0, direct, hold, set to 1 at the bottom. Then for your other controls make sure you set the conditions to either m=0 or m=1 depending if you want them as shift functions or not.

Also depends on the pedal you are using. A latching type will be on in one press and off on the second press. An unlatching pedal you will have to hold down, or set the button action to toggle with each press.
As far as making it a shift key, just make the pedal a modifier. So when it is pressed your modifier will = 1 & when not pressed the modifier will = 0.