Dampro has released some documentation and .ELF (which works very well) to accomplish this task. For example, someone used it on a V7 with a R-type laser and booted the .ELF with an old version of Pukklink/Inlink over the PS2 Network Adapter. The application even detected that it was a V7, and you can make a back-up of your current EEPROM by pressing R1 that saves directly to the folder on your PC were you booted the .ELF from.
You want to make a back-up first so if you get into trouble you can restore the EEPROM to its original state by pressing L1. Then you can select the laser you want to flash the EEPROM to. When you get the the program screen you press start, and its flash operation is over very quickly. Then simply turn off the PS2 and put in a brand new KHS-400C laser and it works!