What I did when I switched to DS Team is just copied all the files from my old image using flash wizard pro "Advanced smartcopy" option. I copied file from /var/bin /var/keys /var/tuxbox/plugins
But you can do the same manually with ftp tool. Anyway for ds team to show emulators in the list when you press blue button you have to edit:
/var/tuxbox/emulist.xml
It looks something like this:
<?xml version="1.0" encoding="iso-8859-1"?>
<emulist>
<emu emulator="Common Interface" osdname="CI" emuscript="" daemon="" filecheck=""/>
daemon should be the name of emu binary, other options you can enter what you want.
As for plugins, having .so and .cfg files of plugins in /var/tuxbox/plugins is enough for them to show under yellow button and to work properly.
Now this is just what I did, more like improvisation. There is a quite longer text on another board that explains how to add plugins and emus properly in this image. But I think it is a little long to read and it is not a must to do in the way they explain. But if you want I can copy the procedure here.