Kohler one-piece toilets

[doc1]

I have two of these.  After having the Korky hinge flappers fail one after another in about 8 months, I switched to the Kohler version.  On one of the toilets, the little black plastic rod went right into the slots.  It has worked well for more than 2 years now.  On the other one (first Kohler flapper after a Korky flapper), I have tried everything to squeeze the little black rod into the slots.  I heated it in hot water, I put a piece of wood behind it and tried to pry it in, twisting with a screwdriver.  My hands are larger than Trump's, but not yuuuuge.  I can't get my fingers behind the place where the rod goes and have sufficient pressure to pull/slide it in.  It just seems to be too big to fit, no matter what I do.  Has anyone else found a solution to replacing the flappers on these toilets?

[Lynden]

It looks like the rod slides into the groove from either end rather than push into the groove from the back? 

https://www.youtube.com/watch?v=KXzYIhhfOuA

[doc1]

Lynden, that wasn't among the 20 or so solutions I tried.  As I look at the rod, I think you are exactly right.  I'll try it in the morning and let you know if it worked.  Many thanks.

[doc1]

Lynden, it took about 2 minutes to install it using your method.  Again, Woodnet comes through.  Thanks, Lynden.