1. Download:

• Office Deployment Tool: https://www.microsoft.com/en-us/download/details.aspx?id=49117
• Extract and take only setup.exe
• O365 ProPlus ISO: https://officecdn.microsoft.com/db/492350F6-3A01-4F97-B9C0-C7C6DDF67D60/media/en-US/O365ProPlusRetail.img
• Extarct Office folder to same dir with setup.exe & cfg.xml
• Edit cfg.xml, field SourcePath, value is parent folder of Office folder

Eg:

C:\OfficeSetup\setup.exe
C:\OfficeSetup\cfg.xml
C:\OfficeSetup\Office\.....

Then SourcePath="C:\OfficeSetup"

2. Install: Open CMD, run setup.exe /configure cfg.xml