[plt-scheme] No plt-uninstall script

I installed plt-scheme 4.2.3 from source using

$ src/configure --prefix=/usr/local
$ src/make
$ sudo src/make install

and now I wish to remove it. However, the Makefile has no remove
target! This list suggests that I'm supposed to have a plt-uninstall
script but I have no such script.

Why do I not have this script? How can I remove plt-scheme?

Thanks,
Richard