Since you are talking about not doing the update, then I guess using software is also out. The only other way is to let the scanner search out the IDs and store them once they are found. Hit the T key to store or the LOUT to store and lock them out.
Update.....found the radio shack usb cord in my parts box.....borrowed my wife's laptop and had a friend walk me thru the GRE download over the phone in less than five minutes and had my 300 updated in less than two minutes. Nice!