Peter, here is a link describing methods to remove the forend off a Trojan. I particularly like the "card method".
http://parkerguns.org/forums/showthread.php?t=19043
Once the forearm is off, with the barrels inverted, you will be able to see the extractor rod tip protruding through the barrel lug and the extractor retaining screw in the mid area in front of the rear lug. You should be able to move the extractor back and forth in the barrels with light thumb and finger pressure. If you decide to remove the screw, be sure to use the right size screwdriver tip not bugger the screw. Also be careful to not put pressure on the tip end of the forend when reassembling to avoid cracking the forend wood. HTH FV