connecting the DDJ-FLX4 to Serato Lite/Pro and Mixxx

hello:

I just got the DDJ-FLX4 controller. 

How do I get it to work with Serato? 
Also how do I get it to work as well with Mixxx dj software? 

I am new to all this (I am old school and used to DJ with CDs, cassettes, and LPs). 

Trying to learn all this.  

Thanks in advance for any help you can offer.