Using winget
If you're using modern versions of Windows 10 or 11, you can install vrc-get with winget.
winget install anatawa12.vrc-get
Using scoop
If you're using scoop, you can install vrc-get from a scoop bucket.
scoop bucket add xrtools "https://github.com/babo4d/scoop-xrtools"
scoop install vrc-get