It is possible to modify your kotor game. the thing is that not every mod that work on pc works on x-box. One thing that is for sure are the ones that create items, if it stands in the readme that you will ned to use giveitem cheat you can flush that mod down the toilet at the second. Though some simple mods like the "HK military droid series" reskin should work without any problems.
To start with you need a ftp program, any that can create files into your x-box, uplode/download files to your x-box and if possible edit them.
First if not done so create a folder named "Overrid" (right now i fell like an imitating parrot).
And now i recomend you to vissit the link i will post because if you are to install mods you will need to have the game on your hd and that will bring up atleast one known bug. Second I don't think the game will find the mods but one thing is for sure you cant play mods with the disk.
Glith on Peragus...help please.
When you read trough this thread and edited the "swdirsXbox.ini" file you should be good to upload your mods now but as I said not every one works.
I am working on a compabilety list but on the cause of always updating with new mods and that some mods are triggerd in a sertain time in game it will take further time if i eveer get it done. But stil if you want to test yourself you can visit some of these sites.
Svöshs kotor mods
Darth333 kotor mods
Pcgamemods.com (My personal favorite)
Team-gizak.org (they are working on a big projekt I can't wait)
Note that most of them only have Kotor 1 mods and you may find several sites with the same mod.