It's easy if you follow the unique way i finished the mission ( no, not with cheats). This method is found by me. The mission is probably one of the hardest mission so i had to think a special way to finish it.

First, don't change the default load, as hellfires are very much needed for this mission.

Press F9 until the waypoint is set to 4 & 5 ( because you don't have to go to waypoint 1,2,3).
Now fly the opposite direction of the FARP, you will notice a yellow arrow pointed to this base FARP, just fly the opposite direction of where it points. Fly low, avoid detection.

There is another green arrow pointed to waypoint 4, when the angle between this green arrow and the yellow one is about 10 minutes, fly to WP4, AVOID DETECTION. ( otherwise the Russian jets will patrol the base where silos are sited, which makes it impossible to finish the mission)

Now you are behind the base which have 3 silos to destroy. The terrain there is very plain. Select hellfire, the nearest silo is in the woods, (that's why you need to use hellfire, rockets will explode when hit on the trees, while hellfire attack from above), lock and fire 2 hellfires, after the silo's destroyed, fly closer, your radar will detect there's another one on the left, far in another forest, lock on it and destroy it using the same method.

By now fly to the third one, it's on the right side of the first silo you destroyed, fly over to the last silo site and use 2 hellfires to destroy it. This one is guarded by SAMs so be careful.

By this time the Russians are probably alerted and the jets are now in the sky, you must fly low, press f9 repeatedly until it's set to waypoint 1, use terrain to evade enemy and make your way to WP1. When the yellow arrow pointed to the base appears again, fly towards it, and then you will win.