you can buy the one with thread on it WGP Autococker Threaded Vertical Feed Port - Fits: 2K/2K2/2K3/2K4 - Raw
simple way to remove the feed if you have a vise is to clamp the feed into a vise and twist the body. just twist it back and forth till it is apart. fbm did sell feedneck without the thread but they are hard to find. another option would be to mod your existing feedneck so you can add a collar to it.
modding stock feed