So, about those instructions. An important thing to know is that the model number of this router is F7D7302, which is just a newer version of the F7D3302. So when you're searching for firmware that's the model you want to use. Now, I've spent some time doing research to get this working with TomatoUSB and finally came with a pretty simple solution. I've noticed a lot of guides want you to install DD-WRT first, which is completely unnecessary.
The best version for this unit right now is the TomatoUSB builds from Toastman. While this may appear to be a lot of steps, it's really not all that complicated.
You're going to want two files for this procedure. Google "tomato toastman 4shared" to find the repository (it's hosted on a download site called 4shared). You'll be looking for the latest version in the RT (MIPSR2) folder (each version will be split into VLAN and STD versions, you'll want the STD one). Inside of that folder will be a bunch of .bin and .trx files. You'll want the .