Hmmm...I'm pretty good with computers and have downloaded and installed probably over a thousand mods between Oblivion and FO3, and I can't for the life of me figure out how to install this.
First, every time I try to extract the files using 7Zip, it tells me the texture bsa file is corrupt wh a CRC error (the only other mod that ever did that to me was GNR: More Where That Came From).
Second, each file contains a texture bsa file that all have the same name and are the same size, but I assume they aren't all the same content, as it wouldn't make sense to have 5 archives with the same bsa file. But if I extract them from the rar file it will just overwrite the bsa file from the last rar file.
I renamed the rar files as suggested thinking that would somehow make my 7Zip program extra the texture bsas and merge them somehow, but it didn't do anything different for me than extracting them manually with the above problems.
I am now sitting through the slow process of downloading the new main archive you posted today to see if I have better luck. I will edit this with my results.
EDIT: Ok, the Main file still has the 3 files, but the texture BSA is much larger than that in any of the individual archives, so I assume it is all the other archive's texture BSAs already merged. However the instructions in the readme state: "download COMM main instead of the 5 packs THEN extract the COMMV10.rar into ..fallout3/Data/"...is the COMM_Main archive all inclusive and is what you are calling COMMV10.rar, so that is all we need?