Well, its a long process in short. Follow the webrtc link:
https://webrtc.org/native-code/android/ if you built it towards android and linux it should cost you about 30gb. after the build its easy to build the latest
libjingle_peerconnection_java.jar file without any hassle.
For your reference: The new jar file you build may contain new functions which must be reflected in your code. In my case, i was using a libjingle_peerconnection.jar which is 2 years old(i think!) which cost me more time to migrate. You can refer AppRTC code for the new functions utilized in that application.