The whys and the hows
I would say no, but I think I would put them in quotation marks. 'The "whys" and the "hows" of apostrophes aren't easy to understand.'
Actually I was searching for something similar today, and I came across this.
I think it's quite similar to what you're asking :
When forming the plural of words and hyphenated phrases that aren’t nouns but are used as nouns sometimes you do and sometimes you don’t:
- I want no ifs or buts.
- Here are the dos and don’ts of blogging.
- I’ve written 25 thank-yous.
BUT
I’m tired of all his maybe’s
Hope this answers your question.