So you don’t have to wait, can import only what you need, and minimize editor crashing… especially if you buy a lot of assets…
Install with chocolatey http://chocolatey.org/
cinst upackx
usage:
upackx [-i] packageFile.unitypackage [-o] directoryName
extracts packageFile.unitypackage to the folder 'directoryName'
Yes! But I can’t unpack some PNG files 
Tried with A* pathfinding project: some PNGs came out nice, some were corrupted. Everything else was fine.
Hi, check this out as an alternative with UI for Windows: http://upu.derfunk.com/
Pretty nice I needed something like this to help fix an object orientation bug from a premade package
Seems like both of the original ones are broken, so I made a new one GitHub - Cobertos/unitypackage_extractor: Extract a .unitypackage, with or without Python
I’ve been trying this, since one of the assets I bought as things like “:” in their folder names, making unity unable to actually extract some of the files from the unitypackage.
Unfortunately, your extractor only actually extracts one file from the entire unity package and then stops.