USB-to-CAN V2 downgrade from 1.06.03 to 1.05.04

Hi, my unit came with 1.05.04 recently I’ve upgraded to 1.06.03 but now would like to downgrade back to 1.05.04 but can’t seem to find “USB-to-CAN_V2_VCI_flash_v1_05_04.hex” anywhere in the download section of IXXAT website.