Postbank does not direct register shares, so you need to transfer your shares to another broker that can DRS transfer. A popular route has been through Interactive Brokers (IBKR).
Please Note; if you have GS2C shares, you can convert them to GME and transfer to IBKR at the same time using this guide
The quickest way is to open an Interactive Broker account, buy a share, and request a DRS transfer (link to guide here). While you wait for your Computershare account to be created, you can transfer your shares from Postbank to IBKR with a Basic FOP Transfer, then from IBKR to Computershare via DRS transfer $5(US) fee.
How to Transfer GME shares:
Once your shares are settled in Postbank, you need submit a transfer request with the receiving broker (IBKR). Then sign the Letter of Instruction IBKR creates for you and email it to Postbank:
Login in your IBKR account, and click on “Transfer & Pay” from the top menu and select “Transfer Positions”.
On the next page select “Incoming”.
On the next page select “All Other Regions” from the drop down menu.
On the next page select “Basic FOP Transfer".
Select POSTBANK on the drop down list.
For “Your Account Number at the Financial Institution“ put your Postbank account number.
For “Name of Account Holder at Financial Institution“ put your full name as defined on your Postbank account.
Select the Account type (most likely individual).
Select the country of the Financial Institution (Germany).
For the contact email put “email@example.com".
You have to add the asset you want to transfer, click on “Add Asset".
On the next page search which stock you'd like to transfer (GME), click on “Search".
On the next page, click on the row “GAMESTOP CORP- CLASS A / NYSE".
On the next page, define how many shares you'd like to transfer and click on “Save and Finish".
On the next page you'll see a summary of the transfer. Write in your name as it shows on the page and click on “Continue”.
Interactive Brokers will then generate a Letter of Instruction for you. Click on “View Form”, then click on “Print”.
Print, sign, and scan back the form back in.
Once the Letter of Instruction is signed, scan it or take a photo of it.
Send an email to firstname.lastname@example.org.
For the Subject write: Outbound Transfer Request (Postbank account number).
For the message write: "Please find attached the Letter of Instruction for authorization to transfer XX of my GME shares to my IBKR account (IBKR account number)".
Attach the Letter of Instruction.
Click on "Send".
The transfer should be performed in 5-15 business days. You will receive an email confirming that the transfer was successfully performed.
After your shares reach IBKR:
Now you are able to request the DRS transfer from IBKR to Computershare. To do this you can follow our guide on how to DRS transfer from IBKR (link to guide here).