Firstly, I read an old post where someone said this is possible with a little finesse. That person is either a serious knuckle-dragger, or they don't work on their own car.
I did not have to loosen the cams. A word of caution when using the compression tool. The bolt on mine bottomed out on the head before it was compressed enough. Keep an eye on it, and finish compressing with the tensioner loose.
1
Remove a ton of stuff.
2
Lift and support the fuel rails by about 2", and bend the metal coolant pipe out by about 3".
3
The real problem. The vacuum unit covers 2 of the tensioner bolts. There's no hope of getting to the back of the head. So...
Remove the allen bolt holding the upper bracket on the vacuum unit above the cam chain tensioner. I had a good nights sleep trying to figure out how. I considered unbolting the sub-frame and sliding the motor forward to get to the freakin' bastard. Finally, I used a quarter drive racket, 5mm socket, and 5mm allen cut off to fit. Then using fingertips I could drop it in place, slide a cheater bar over the end, and move it about an inch. I did this about 12-15 times not knowing I was actually moving the bolt. I was super happy to feel a loose washer when I looked for another method. I finished loosening the allen head with an 18" 45deg needle nose plier. I pried the unit back with a pry bar until I heard a crack...just enough. Hopefully, I didn't break anything. Notice one tensioner bolt still cannot be removed until you loosen and tip the tensioner.
A molded piece of silicone used in a completely wrong way. Seriously, come on.