Thanks again for your kind answer..
I can make the .so file and put it in that directory. However I still have final question that following the 21 step that I have to put this line inside the /etc/samba/vscan-clamav.conf.
vfs object = vscan-clamav vscan-clamav: config-file = /etc/samba/vscan-clamav.conf
Is it correct? I have tried it already nothing going wrong and no error message after reboot.