Blades without sharpening notches

What’s the best way to sharpen that last 3/16 of an inch that can’t be reached with the stones?

Do I need to grind off the plastic so I can get the stone right up to the ricasso (I think that’s the proper term).

Thanks for any help.

Grinding off the plastic is one way. Another way, which I did, is to make a sharpening notch in the knife (I did this on a Spyderco Tenacious). And of course you could settle for a little unsharpened part of the blade. But really, I don’t understand why they design such knives. Definitely not with use/sharpening in mind.