ok, I assume by editing you mean creating.
first, you need to make the model in either 3d prog you want. Make lods, thrusters, turrets, whatever, at your own discretion. then you have to convert to cob, coz the hierarchy stuff can only be done in truespace. If you look around, you'll find many descriptions of the hierarchy making process. When this is done, you need to convert it to a pof file. Use Kazan PCS for this. You'll have to edit, still with PCS, al the stats of the pof file (gunpoints, engine glows etc). Once this is done, you'll have to modify the ships.tbl file thanx to wordpad.
For more detailled stuff, just ask, I give the hand to someoe else
