After opening the R-Link Explorer, you must open the SD card on the left panel first.
Than you will see TomTom.000, Tomtom.001, etc. on the right panel.
Open TomTom.000 on the right panel and go to the common/installed/ map and there you must copy the new map to.
By the way I am not familiar with the Carminat tomtom. So, I don't know how it works exactely with patching.
Peter