Install the package first with slacker and disable the fw NFS package. After that, create the /ffp/etc/exports file (or if it is exist, skip this step) and open it for editing via nano, vi, mcedit or etc).
And here You Can create the shares. For example mine external HDD sharing (with access of anybody on my network) looks like this:
Change the <longUUID[...]> to fit for Your environment and finally save that file. Now, You just have to start the package and make the script executable to start the unfsd server during every FFp startup:
chmod +x /ffp/start/unfsd.sh
And that's it. You are done!
Ps: change the subnet from 192.168.1.0/24 if necessary. And use the Google if You looking for some other nfs config option.
Thanks nas-central the lot of help!