First make sure your eeprom is backed up. if you have australian rats nkp-config program, then put the source and xbedump and nasm all in the same folder with it. run his program, select the options you want, click finish or whatever the option is to build it and it should create the config how you want it, and if you have everything else in place, it should compile and sign nkpatcher and give you a .xbe that is ready to go.
to put nkpatcher into your xbox, replace the pbl .xbe with nkpatcher making sure they are named the same and make sure all your other files are in place.
you might want to try this
Link, to help you update your softmod.