So here we go 
To upgrade Amanero firmware you shoud Download tool www.amanero.com/oemtool117u.zip
Erase the board (like no the picture) www.amanero.com/erase.jpg
Run ConfigTool.exe and insert on the first form shown oemid nativedsd (replacing combo384)
at the bottom of the available firmware list selector box there is for
CPLD CPLD_1082_8804_TXRX firmware_2006be15r2_8804_TXRX
select CPLD_1082_8804_TXRX
Press FLASH CPLD
then when done select
firmware_2006be15r2_8804_TXRX
and press FLASH CPU
it installs the native dsd support with 8804 rxtx
PS Amanero to replace firmware should be connected via USB to the computer with installed drivers.