I recently acquired a really nice, barely used Cannondale T700. I need to swap the handle bar but cannot loosen the bar end shifter pods. Shimano 8 speed. I've removed the shifter parts and located the 6mm Allen bolt and understand that it turns clockwise to loosen. It won't budge. I sprayed some WD40 and let it soak overnight, still stuck. Any ideas? Thanks.

other than different liquid wrench type products, and ammonia
[see the many threads on stuck stems and seat-posts]
there is the last resort of sawing off the end of the handle bar ..
the replacing the handlebar..

I know when I was too gentle with my bar end shifters it felt like they were locked in place, the next time I applied more force then I wanted to and it unscrewed no issue.

How long is your allen key? Shop keys are longer than whats found in consumer sets and 'multi-tools'. You might need some extra leverage to coax the hex bolt to start out.

Sometimes my bar end shifters get stuck in really tight. Getting a long allen key or putting something over the end for more leverage and then really giving it a jerk has always gotten them loose. Be sure the allen key is really in there all the way so you don't round it out, and if you do, stop immediately (but then I don't know what to tell you to do.).

+1 Those things seem to like getting stuck. Honestly I doubt it's corrosion or some issue like that, but rather once they're tightened down they don't want to move. The threads on those bolts probably never get greased because that would require disassembling the little clamp mechanism and no one expects them to get stuck like a seatpost or stem.

More leverage should do the trick.

Thanks all, I'll try a longer handle on the Allen.