Blender can do that (for years now) and does a pretty good job too!
In your Kitbash3D scene, go to File > External Data > Find Missing Files, point Blender to the KB3D Textures and let Blender go to work! 
Caveat: in this case there are a truckload of textures to find and load so be patient. Depending on your machine Blender may even crash…it happened to me 
but I’ve got an older computer.
In less intensive situations, Find Missing Files works great just pointing Blender to the general directory where your images may be. Now, if you’re pointing Blender at / (root) go get a coffee because it has to search your entire hard drive!
After you’ve found and loaded the missing image textures, a great tip by that madman Gleb Alexandrov is to Pack All Images into the .blend file and then Unpack All Into Files into a directory where your .blend file sits. That way you don’t have to search for them ever again!