After clicking this link https://ziel-verlag.de/grundlagendweiterbildung/essential-readings.php
this windows opens: First accept or change the number of copies you want. Then click bottom right to go on:

Now opens the next window: Here you only have to click bottom right to go on:

 

The next window asks for the address where to send the book(s) to. *If you find your country not in the scroll list send a mail to ferstl@ziel.org. He ist the publisher, and is very helpful to make it possible that you get the book.

Now you check your address, then go on:

Next page: postage and go on.

Select payment method:

Mostly nothing to do:

Final page. Check and confirm payment.

Finished!