For my Celestron Nextstar SE I simply added a cheap Bluetooth module into the Hand held controller.
There are many different versions of the controller board so there are many different instructions available. One is here:
In my device it was a version where no instructions were availlable but it was easy to identify the RX and TX line between the USB chip and the microcontroller (which is the bigest chip inside). It was also easy to find a line that offers 3.3V for the HC06 bluetooth module. Adding a small switch into the data line allows the choice of USB (for SW updates) or Bluetooth (for normal use).
It works fine with Stellarium software on my laptop and WiFi is still available for internet connection.