This simple guide will teach you how to transfer your World War Z Aftermath save files from Epic Games Store (EGS) to Steam.
Before you begin, make sure that you have completed the installation of WWZ Aftermath from your Steam client. The entire process only takes four major steps. Read on!
Step 1: Go to the file directory for the EGS save files
Open your File Explorer and go to:
C:\Users\user profile\AppData\Local\Saber\WWZ\client\storage\slots
Look for the for file name user_progression.dat and copy it (Ctrl+C).
Step 2: Go to the Steam Cloud directory for WWZ
Find the installation folder for the Steam version of World War Z Aftermath. The default location should look like this:
C:\Program Files (x86)\Steam\userdata\your steam user ID\699130\remote
Step 3: Replace the user_progression file
Delete the user_progression file located in the Steam folder (from Step 2) and replace it with the EGS user_progression.dat that you copied from Step 1.
Step 3: Rename the user_progression file
Rename the file from .dat to .cfg.
Step 4: Launch World War Z Aftermath from Steam
There you have it! You successfully carried over your WWZ user data from Epic Games to Steam. The next time you launch the game from the Steam client, you should be able to pick up where you left off.

World War Z: Aftermath is a co-op zombie shooter game developed by Saber Interactive for PC, PS4, and XBox One. The game was published on Steam last September 21, 2021. It is the first expansion of World War Z (2019), the popular third-person shooter that launched on the Epic Game Store in April 6, 2019.
Now go forth and fight back the zombie menace around the world! Remember, WWZ is so much fun to play with up to three other people. But if you prefer to go solo, then good luck and may your aim be steady and true!