This method is meant to ludicrously enhance the speed of grinding a player's Legend Rank from weeks or months to one simple hour. This method is made up of a couple glitches that requires the capability to play online with others and the involvement of duplicating Disaster Relief Packages (DRPs). It can be performed at the beginning of the game once you are able to retrieve DRPs, but it is highly recommended that you reach maximum Survivor Rank before doing so as it will take more time. You can use this glitch for reaching both maximum Survivor Rank and maximum Legend Rank, but not at the same time as all achieved experience will go to only one skill tree at a time.

Below is a small chart of how much experience is granted with each DRP that is turned in to a Quartermaster by whichever difficulty your game is at, along with the total number of DRPs needed to reach Legend Rank 250 after maxing out your Survivor Skill Tree.

Each DRP = ------------------------------> # of DRPs =
12,000 exp (Normal) -------------------> 56,250
30,000 exp (Hard) ----------------------> 22,500
120,000 exp (Nightmare) ------------> 5,626

Step 0. (Optional)
Gain maximum Survivor Rank (either through this method or regular gameplay, otherwise a lot of DRPs will be wasted if you're not already maxed out in your Survivor Skill Tree).

Step 1.
Gain any number of DRPs from in-game and head back to The Tower (or any other safe zone), go to your stash.

Step 2.
Drop ALL DRPs from your inventory into your stash.

Step 3.
Join another player's game, but insure that you are joining a session that is in the same game cell and mission as you are - Inside or Outside - failure to do so will make this method unusable and guaranteed to never reach Step 6. (The first floor of the Tower is registered as "Outside")

Step 4.
Find the nearest stash and face it, but DO NOT open it.

Step 5.
(This part is tricky, you have to be fast with your thumbs)
Open the pause menu and select to drop out of the other player's game. Immediately after doing so, exit the menu and spam the open button, the stash menu should appear as the screen turns black and reverts to your session.

Step 6.
Once you are back in your own game session, the menu for the stash should still be open, DO NOT close the menu. Drop the DRPs as many times as you want, it will not disappear from the menu (you will have to move to another item in the stash then back to the DRP to drop it again).
If you haven't reached maximum Survivor Rank, around 400 - 500 DRPs will suffice for you to max the skill tree on Nightmare difficulty.

If you don't have at least one batch of x99 DRPs, you can repeat step 6A until you have a full batch, then repeat steps 3 - 6A, otherwise it will take significantly longer to reach the number of DRPs needed.

Step 7.
Close out of the stash menu and collect all of the dropped DRPs (Maximum is x99 at a time), you may be partially blinded depending on how many times you dropped them.

Step 8.
Save, then quit your game to change the difficulty to "Nightmare" in the main menu, this will give each DRP a x10 multiplier on how much experience is granted.

Step 9.
Go to the Quartermaster and turn in all of your DRPs. (Remember, if you haven't maxed your Survivor Rank, you will have to do this again regardless of the millions of XP you've accumulated)

This method can be used for everything that can be put into the Player Stash, it is not limited to Disaster Relief Packages. Feel free to duplicate any item this way whether it be melee weapons, firearms, throwables, medkits, or any other item that is limited to a number in your inventory.

Good Night, and Good Luck!

Kayaus, Xbox One