switching shift knob
 

k first of all newbie porsche owner have a 2002 boxster living in germany here as an american problem is i want to switch the old shift know but in order to fit a new one on there it has to go over the rectangular rod on their now and the new knobs are circular problem is with the euro rate a new 987 knob from porsche is 300 dollars and all i want to do is switch the knob i even considered grinding down the rectagle and making it a circle please help