<VV> Replacing FC Ventilator Window Weatherstrip

[Ron]

How does one install a new molded weatherstrip for a FC ventilator window?  The friction spring assembly is supposed to go through a hole in the rubber.  Should the pivot rivet be drilled out so the window can be removed or does one cut the super expensive weatherstrip on the inside so it can go around the lower pivot?  What has worked the best?  Or, am I completely missing something?
RonH  ('63 Rampside)