To do this you need to completed the arms week weekly challenge(which rewarded you 90 event token, 350 bright dust and some event xp) Then create a new character (if you have 3 characters already, you need to deleted one of them and create a new character) After create your new character simply go back to your main character (which like i said already completed the arms week weekly challenge) you will find out your arms week weekly challenge is refreshed and completed again(click to collect reward that i mentioned earlier), beside this you can also complete the first misson on the new character(Birth of A Guardian), then you can go the shooting range talk to Ada-1 to pick up the new Hand Cannon(Phoneutria Fera), which is a Prime Engram in Energy slot (+3 to your account power). You can do this Infinite times as you want. Unfortunately i dont have a vid for this, i was told that this can be done and i seen people already got thousands of bright dust from this.