(run from the commandline exactly as is here)
sed \
-e 's@NAME@x11-ssh-askpassg' \
-e 's@VERSION@#1.2.4.1#g' \
-e 's@DATE@September 17, 2001#g' \
<x11-ssh-askpass.man.in >x11-ssh-askpass.man.tmp
mv -f x11-ssh-askpass.man.tmp x11-ssh-askpass.man