Turns out that I need to change my SIM card once in a while.
Do do so, it is necessary to remove six screws from the main case plus two screws for the mPCI LTE card. Now, I am looking into ideas how to improve this.
After some goggling I found this product:
https://techship.com/products/sim-card-ext-push-slot-16/
Looks quite promising (when I can manage to mount the extender).
Anyone else having the some ideas or even solutions? I would be interested to hear.