The Bastard wrote a guide how you can flash your TSOP without opening your Xbox. Of course you still have to link the 2 jumpers on the board to unlock the TSOP write ... but in this guide it's done through the venting holes of the Xbox. (only works on xbox v1.2+ ... as older xboxes have points on bottom of board).

WARNING this procedure CAN be dangerous to the health of your Xbox if something goes wrong or you are not CAREFUL. Please read ALL of this document BEFORE attempting anything contained herein. Using this method you take a pretty big risk (short out random stuff) to blow up your MCPX. It's a nice idea ... but if you wanna play safe, you better just open your xbox if you want to flash your TSOP.