I have a 2003 Klein Attitude Comp, and I want to put a crankset I have on it. However, the crankset is square taper and the current bb is not. Does anyone know what size square taper bb can go in this model, if at all?

I have a 2003 Klein Attitude Comp, and I want to put a crankset I have on it. However, the crankset is square taper and the current bb is not. Does anyone know what size square taper bb can go in this model, if at all?

I found this picture on google search. Note that the 2003 model is candy apple red.