How to Install the OBB File (APK Expansion File)
1-Firstly, Download APK file of the app Microsoft Word v16.0.7030.1017 for Android.
2-Copy the APK file to your Android devce's SD card and Install it.
3-Download, Unzip and Copy the *.obb file named 'main.1638231014.com.microsoft.office.powerpoint.obb' into the Required Location:
/SDCARD/Android/obb/com.microsoft.office.word/
4-The full/absolute path of the obb file should look like as the following (Case-sensitive):
/SDCARD/Android/obb/com.microsoft.office.word/main.1638231014.com.microsoft.office.powerpoint.obb (81.09 MB)
5-If there is no such location, you need to create the path or folder manually on your SD card.