Same, i will be happy to show you, i will try and give you a brief tutorial;
1. Go to where the M14 is respawned, near it you will see an explosive barrel.
2. Jump up onto the fence, then once your up look to your right so your facing the side WHICH doesnt respawn the M14 (to your right).
3. Now you should see a wall with some diaganoll pattern windows.
4. Sprint and jump to that wall but jump onto the bit which has wood sticking out (if you can strafe that is even easier).
5. Once in you will be in a room ,go to the end window and look out and fall out. Once there you will be in a small inclosed area.
6. Set up a freeze jump between the M14 and where the S&
bomb is and land on the building with the water thing on top.
There, skywalking district
If you want a better discription, then search it on youtube.