Hello
You need some 80 girls too, for the first fusion
On the lab window, click on the fusion button. You will see your hookers (you can swith to your actress with the button on the top right). The girls you can fusion will be on top and have a green frame around them. Select the girl you want to fuse (green frame or not), and you will have the list of the girls you need to sacrifice to upgrade her.
Once you have the girls needed, you must select, for each type, which girls you want to sacrifice, in spare body storage and active girls, and click on "fuse new girl". If some of the girls you selected aren't from spare body storage, you will have a warning telling you the girls will be lost. Confirm and the fusion will be done.
To raise the sex appeal of the upgraded girl, you must go in genetic upgrade and use hormone
Hope it can help you^^
