trouble with editing metadata

[james244]

hi there
i have 3 ebooks in mobi format and all i want to do is to edit the metadata, ie the author and the cover. these are personal books.

when i try and add to the name and then generate a new cover, i then press ok and calibre creates a cover and and meta data file

i then load these onto the documents folder on my kindle paperwhite
but the original book details still show up.

maybe the metadata has somehow been embedded in the actual ebook?

does anyone have an idea on how i can resolve this?

best wishes
james