How to open an example application project

Hi.....i have worked  with 'Getting started with the Contiki OS/6LoWPAN on STM32 Nucleo with SPIRIT1 and sensors expansion boards' and have been successful in creating a 6lowpan network and getting access of the sensor readings on COAP client through sensor-er-rest-example......the thing is that i want to create an application so that i can get the readings of an untrasonic sensor connected to one of the GPIOs of the nucleo board ....but i am not sure how to open and modify the sensor-er-rest-example project in a compiler (eg:keil).... Can any one plz help me find a solution for this , or provide me with a project where i can get to access the sensor data on COAP in 6lowpan network.