Although I don't think this will appeal to many folks, but I'm posting it because I believe in trying to share information. These auto forums have been hugely helpful to me, and I'd like to return the favor whenever possible. This came about because I personally don't care for any of the other ways of removing and installing the crankshaft pulley (aka harmonic balancer) bolt, for an Aveo automatic tranny. But I was really impressed with the design that Honda uses when I did the timing belt job on my daughters Civic. Their method uses an insert built into the crank pulley itself, which provides the way to lock the pulley while removing the bolt. So this method is a home-brewed version of the Honda approach. I'm sure that those using the typical methods of handling this job will continue to use them, and I'm not trying to convince anyone to switch to this if they've had success with something else. But if anyone is looking for an alternative approach, you might want to consider this. I was very pleased how it worked out, and now wouldn't consider doing it any other way. So FWIW, here's how it goes.
The first pic below shows most of what's needed. On top is a standard Honda 50mm crank pulley bolt removal tool, which costs around $20. in the middle are 4 metal locking tabs. These tabs slide into the 4 open slots on the back, outside edge of the pulley. They are 1.5" wide, which is slightly less than the width of the slots, resulting in a snug but not binding fit. The stuff on the bottom is a bunch of miscellaneous pieces of metal, which are used to fill in the gaps, as shown in the pics to follow.
The second pic shows the tabs inserted into the slots in the pulley. The one on the top left is partially out of the slot to show how they fit into the slots.
The third pic is with the pulley removal tool inserted into the opening formed by the tabs. This fit is just snug enough to require the tool to be tapped into place with a small hammer. It's immediately obvious from this pic that this is not yet a solid arrangement. The tabs form a square, and would not stop the hex-shaped tool from turning.
In the fourth pic, the key to stopping the tool from moving is the extra pieces of metal, which are inserted into the various openings. Although this looks kludge, it's highly effective in locking the pulley tool into place. The 4 tabs are pinned into the pulley slots, and the extra metal pieces bridge the gaps and completely lock the tool into place and prevent it from rotating inside of the pulley. It's essentially a simulated hex opening, and was rock solid for both the bolt removal and also the reinstall of 80', 30,15.
The final pic shows the full setup using 1/2" extension, breaker bar, and a jack stand to keep everything steady. And although it's hard to see, there is another breaker bar which is attached to the pulley removal tool, anchored at an angle to the ground.