How do I configure the registers in the CN0540 (AD7768-1)?

I have bought all the parts of the CN0549 system

I am trying to change the filter settings of the CN0540 (basically the AD7768 ADC)

I have read the user manuals and see the registers listed in the AD7768 guide. The CN0540 talks about how different parameters  can be set to adjust the filter operation (table below).

I am looking to change the power mode, MCLK ratio, filter decimation rate and -3dB bandwidth

There is also a simulation tool for the AD7768 that I have looked at and a similar query in this discussion forum about AD7768. 

The recommendation is to use SPI - I used the IIO Oscilloscope software and ran it as admin and accessed the debug mode. But am unable to even read the register contents in SPI mode.

Am I supposed to connect it to a microcontroller and issue commands over SPI? If yes; what is the format of the command? I would like to read the default register settings first and save them before making any changes.