Unfortunately you cannot place the pianobook instruments in the Kontakt library (a juicy fee has to be paid to Native Instruments to do this. Ask Spitfire). Just place your instrument in a folder on your computer. And navigate to it using the files tab on Kontakt I have a folder dedicated to the pianobook on a drive for samples,and they are all easy to access. Unless your version is an old version of Kontakt 5. That’s what you have to do.