Kiwo

hey guys i need help so im following the install guide and up to point 10. everything works fine ive tested it and all is good, now the second part to get the Additional Mods, so i select everymod thats listed, i press on Apply changes then i get to the next tab" changeset" and it tells me that everything will be removed and the new stuff is gonna be added, i dont know how to combat this its driving me crazy and the guide says nothing about this so please i need help !