before you take up such a tour,
I'd recommend to please take road trip within Pakistan over following route. This will help you know your driving skills, endurance and the vehicle capability to handle such routes.
Abbotabad, nathia gali bhurban muzaffarabad garhi dupatta hattian bala sudhan galli bagh & rawalakot.
if you can handle this track in a 660 Alto with one night stay and zero car failure please do plan the cross border trip with necessary paper work.
you shall have High Visibility Jackets, a tow strap battery jumper cable and a portable compressor to inflat the flat tyre(s).