Despite the title, I envisioned it more like Robert Heinlein's novel The Puppet Masters, with a parasite attached to each gal controlling her thoughts, rather than they being physically replaced.
I love this. I often imagine a story with a scene like this. Taken women needing to be inserted to download and upload information...as well as feeding from alien nitrients to enhance their conversion. Mmmmm...how I dream of being one of them.