ADF5610 Modes of operation

Good day, I am programming my second PLL device and I am kind of struggling getting into the right mode of operation in the ADF5610 evaluation board. I have used the ADF5610 Evaluation board software, so now I am trying to communicate with the evaluation board as a slave using a microcontroller(master) through SPI. Now, to initialize the registers in ADF5610 it needs to be in either Open Mode or Legacy Mode and that is determined on power up of the device. I have tried multiple ways of getting in one of the modes but I can't seem to get it to work. I am looking for something a little more detailed than what the data sheet has, like a sample/pseudo code when trying to get in one of the modes in able to initialize the registers or help me understand the steps in getting the right mode during power up. I read the there is an active high CEN that powers down the PLL section, will I have to toggle this to get the right bits/state for selecting the one of the modes? thanks!