First, obtain the files:

fvwm-2.0.45-stroke.patch
fvwm-2.0.45.tar.gz
fvwm2rc-stroke.txt
libstroke-0.1.tar.gz

From http://www.etla.net/~willey/projects/libstroke

Compile the libstroke library.

To apply the patch:
cd /path/to/clean/directory
patch < /path/to/patch/file

then:
edit Fvwm.tmpl to point Stroke paths to place where stroke lib is installed
xmkmf
make Makefiles
make

You may need to force compiling with GCC via the Fvwm.tmpl as well.

Add the Stroke section of the .fvwm2rc file and have fun!