Copy them to a USB stick & use the media adapter to USB or copy them to an SD Card.
What is the info you SEAT Dealer gave you?
VW have a logo pack on their site – same ICE system in Golf as Leon & Octavia.
At the bottom choose your country

http://webspecial.volkswagen.de/infotainment/de/de/manuals/stationlogos.html?d1=discoverpro-2

Current Logos
To install the logo on your system:
Save the file by clicking on the link easily to your computer in a folder of your choice.
Unzip the zip file and locate the relevant logos from you.
Copy this to a SD card.
Connect the storage medium and then to your Infotainment system.
You can now import the desired logos into your device.
Do this, tap the function area Setup and then channel logos.
Now tap the desired number button that is to be assigned to a logo.
Select the source on which you have saved the image (eg SD1) and then select the logo.
Repeat this process at the request of other logos and finally return by pressing the radio button to the main menu Radio.
The SD card can then be removed.
We offer the channel logos in ZIP format for Germany and many other European countries. The logos are provided only for use in our radios. Any other use is not permitted.