Camshafts Not Aligned Correctly

I recently noticed that my exhaust and intake camshafts were not aligned correctly (the engine was recently rebuilt). The alignment tool for this engine is a metal bar that runs across the end of the cams horizontally, and a pin to hold the crank at TDC. I tried to release tension off the timing chain to rotate the one cam, but that just made matters worse some how. Is is feasible that I just remove a sprocket off one of the cams, to release the chain, and then line everything up correctly? I'm trying to avoid having to remove the timing chain cover. Anything I need to worry about?

2.3L Mazda 3 DOHC

I doubt you can fix this without pulling the cover to release the tensioner.

Why do you say that? Once the pulley is off the exhaust cam, what would be preventing me from getting both cams in alignment?

Lining up the camshafts without the sprocket on will be a very tedious task. Then you will have to fight the gear back in there while its under tension, without spinning either cam or the crank.

Well I didn't need to remove the sprocket. Once tension is released, I can loosen the exhaust sprocket which allows the cam to move freely.

That being said, I had an issue where after I got everything lined up with the tension released, I would then rotate the crank to tighten the chain backup, and then everything would go back out of whack.