GTV2000 Seat reclining mechanism knob installation

I need to replace the seat reclininging mechanism knob on a GTV2000. I have a replacement knob complete with chrome plastic insert and my mechanism appears to be okay otherwise - just missing a knob. There is a 3-point star wheel (not sure this is the right term) to which the knob attaches. One side of the tips of the star wheel are turned up slightly. The points of the star wheel which are flat and about 10mm wide go into slots in the knob but I couldn't twist the knob onto the star wheel without applying what I considered unreasonable force and I don't want to break the knob. Do I have to disassemble the mechanism to install the new knob or can it be installed without disassembling the mechanism?