hi i have flahed my xbox and i have downloaded a few games and i was wondering how would u go about modding an ISO of a game, for example dragons origins.

u hav to find the correct file, decompress it, mod it, compress it, then burn to a disk. I think thats how you do it... but theres rsa checks n checksums n stuff so im not sure if theres a way to get past those without a jtag'd xbox...

Not all games have RSA Checksums. MD5 should be all you need for most iso's

Not really....
MD5 is an algorithim used to calculate a 128bit hash value.
when you use a rehasher is repairs any damaged hashes in your hash table within your file.
For games you wan't to mod you need to find a file that contains what you need to edit.
Lets take GTA for an example. It has that Common.rpf (Most games would not have this) Within the common.rpf there are .xml files you can edit them.
Some games may have this check. some don't
Cod WaW has one for Muiltyplayer but not for the normal default.xex
RSA signatures aren't always the method of sigingin it.
Sometimes games uses Hashes. as a form of sigingin it.

You don't need to repair anything there isn't a hashtable in the files
Container files only has the hashtable (Container = CON)

is there a program flying about that does this??