Go to Long Night of Solace (mission start), kill an elite and a grunt (plasma rifle & pistol).

Then run to the station entrance, kill the elite with the concussion gun and go up the rocks next to his pod.

Then when the pelican comes, shoot the concussion gun at it 2 times (armor lock), get on to the wing and crouch and walk over the middle.

When it takes off you need to be on its left tail (armor lock). Then after it wears off jump toward the rocks you can't reach on foot and look for a Seraph you want.

Charge the plasma pistol and shoot when it is going to pass, then follow it, pilot it and crash it into another one. Then simply go find it and have fun!