The reinstallation of the print head assembly is a bit more complicated because you will need to create some sort of bracket piece to hold together the corner section that you cut through. For this I purchased some corner brackets from the local hardware store and cut them in to single smaller pieces that I could use. You can see these brackets in the images. I just chose them because they were cheap and I figured they'd be easy to modify, but you can make other brackets as you see fit.
Once I had the brackets made I needed to mark where I wanted to drill for the bolts to hold these brackets in place. This process was simple for the bottom section. I just decided where I wanted to put the supports and then marked for the holes and drilled. Once I had those holes drilled I attached the bottom portion of the brackets so that I could line up the print head assembly and mark where the top holes should be drilled.
To make sure the top holes where in the right spots I went ahead and inserted the 2 spacer bolts on the right hand side where the two screws attach to the printer base. Once those where attached I aligned the brackets with the cut corner and use a level to make sure the assembly was in the correct position before marking the hole locations. At that point I removed the assembly again to drill those holes and then reattached the entire piece this time using screws and the brackets I had create to secure the entire assembly in place.