Here is a guide on how to install an XAPK file to your Android device via adb on a Windows machine:
Rename your .xapk file to .zip.
Unzip the file to a new folder.
In the new folder, you will see a few .apk files, and sometimes also a folder Android which includes a .obb file (you can ignore the following files: icon.png and manifast.json).
Open a Command ...