What's the correct procedure for upgrading?

I hope nhc-bugs is the correct venue for this question.

I installed NHC 1.16 on Cygwin (Windows XP), had some problems with it,
and then realized I had grabbed an old package.  I'm going to upgrade to
1.18 and try again.

However, I'm a little bit concerned about the right way to do it.  I
haven't found any instructions for upgrading properly.

Do I just install 1.18 and forget about 1.16?  Or should I delete all of
the 1.16 files first?  I didn't see a Makefile target "uninstall",
although there are some "*clean*" options there.

Perhaps you could add this topic to your website?

Thanks.

Charles Hethcoat