You probably won’t find Autodesk 360 Desktop sync install package for download online, but you can install it “standalone”.
- Find some Autodesk install media
- Look for a subfolder named Cloudsync (make sure it is beneath x64 or x86 as appropriate for your system)
- Copy this folder to USB or a network location
- Run the file AdSync.msi on the PC you want to install Autodesk 360 on
- After install, you will need to restart
- After restarting, you may need to sign in using your Autodesk ID
I have previously described how to use Autodesk 360 as a cloud storage location for Revit (and any application) here:
Access Autodesk 360 files in any application, including Revit
Some paths that may assist – these were from BDSU2015:
Building_Design_Suite_Ultimate_2015_English_Win_64-32bit_dlmx64ComponentsCloudsync
Building_Design_Suite_Ultimate_2015_English_Win_64-32bit_dlmx64ComponentsCloudsyncAdSync.msi