I am in the process of resurrecting my Eq5 Pro so it is compatible with ASIAir Mini. The first step is to build an EQMod Direct USB cable. While it is possible to buy one pre-made, since I had all the parts I decided to build it myself.
Based on this colour scheme, the connection to a USB-UART adapter is as follows:
Plug the RJ45 end of the cable into the hand-controller port on the control box and the other end into the ASIAir Mini. Then power up the ASIAir Mini as usual and use one of the 12V outputs to power the SynScan. Make sure to switch on the SynScan as it has its own power switch. After this select EQMod for the mount model and leave the baudrate at the default value of 9600. Tap the enable-toggle-switch and the ASIAir Mini will attempt to connect to the mount. After a successful connection you should be able to manually slew the mount in RA and DEC in Preview mode.
Update: I have to power up the SynScan after the ASIAir has fully booted (made it's beeping noises) in order for them to communicate successfully. If both are powered up at the same time, something goes awry and the ASIAir Mini will not be able to connect.