To build all programs in psmisc, simply execute

    make

To install fuser, killall, pstree, and their man pages, run (as root)

    make install

fuser is installed in /bin, killall and pstree are installed in /usr/bin

pidof is not installed by  make install  because different versions of
pidof exist and may already be installed. If you want to install the
pidof that comes with psmisc (and its man page), simply run (as root)

    make install-pidof