Not sure what you mean by "casket".
The valves (cartridges?) are screw-in. With the handles ermoved, use a properly sized spanner and support the tap body properly.
You'll have probably already found the installation instructions on the Franke website when you DID A SEARCH FOR YOURSELF but just in case, here's the link:
http://www.franke.com/content/kitchensystems/uk/en/home/products/bymodelrange/taps/mythos.html
Click on th emodel name of each type and you'll be taken to ap age that includes the installation guide, which has a nice exploded diagram of all the bits.
XX, September 2015
