Downloaded the file, read the instructions, turned on the MixPre, plugged it into the mains, connected MixPre to the computer, put the MixPre in File Transfer mode, copied the file from the computer, took the MixPre out of File Transfer mode, chose Update Firmware from menu, updated the firmware, auto re-booted.
About 2 minutes. It probably took longer to write the list.
All working fine..
Dominic