the parts inside an SE are the same as the ones inside a TE. the only difference is the inside of an SE is smaller than the inside of a TE. there should be enough space for most mods inside an SE
you have to take a controller for the system in question, snip off the end that goes into the controller (not the end that plugs into the console) and put the individual wires into an ethernet ender. USB is easiest to do, whereas a controller like a PS2 is slightly more complex.
this is easier to understand when you see pictures and i have a guide i would send you but alas SRK is down.