Totally, but you are not paying attention either. The bolt that passes thru the “spring arm” of the tensioner (red arrow) can only be removed after the combination belt tensioner housing/hydraulic pump mount has been removed from the top of the engine (read a lot of work, and direct from the OEM 13 volume service manual set). The bolt you are having trouble with needs to be screwed all the way back into the spring arm (towards the pulley) before the arm can swing freely and the belt removed. I am suggesting that you try to screw the bolt back into the position it is supposed to be in rather than try to remove it, which cannot be done with out getting at the back of the housing it passes thru to remove the “tensioning element” (Porsche for the tensioning spring assembly) and then pulling the spring arm forward. But to get to that point, the power steering pump (green arrow) and AC compressor (yellow arrow) has to come out of the way, the housing unbolted and the tensioning spring assembly removed……………….
In this straight on shot of a 996 motor (same layout as yours), you can just see the tensioner arm (coming off #7) going back into the big aluminum bracket that holds the powersteering pump (#1). The AC compressor (area #5) is already off in this shot.
And this is what the arm looks like out of the assembly:
Try and get the bolt back in, you will save yourself a lot of grief if you can......