I need information on how to connect pixhawk via a WiFi router to my laptop to extend the range a bit and need to know if there is a step by step guide or if any one would be able to help me through the steps here.
Hi,
It would be easier with a bluetooth/serial board which on one end connects to the UART/Serial telemetry port of Pixhawk and on the other end connects via bluetooth to your PC running your ground station.
These bluetooth boards are dirty cheap at hobbyking : http://www.hobbyking.com/hobbyking/store/_42845__Multiwii_MWC_FC_Bluetooth_Module_Programmer_Android_compatible.html
If you really want Wifi and not bluetooth, you could get yourself a ESP8266 module and flash it with a firmware that makes it a Wifi/Serial transparent bridge.