Run Command Prompt (cmd) as Administrator, copy command below and hit Enter.
(XXXXX-XXXXX-XXXXX-XXXXX-XXXXX - activation key)

if exist "%ProgramFiles%\Microsoft Office\Office16\ospp.vbs" cd /d "%ProgramFiles%\Microsoft Office\Office16"
if exist "%ProgramFiles(x86)%\Microsoft Office\Office16\ospp.vbs" cd /d "%ProgramFiles(x86)%\Microsoft Office\Office16"
cscript //nologo ospp.vbs /inpkey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
cscript //nologo ospp.vbs /dinstid>step2.txt
start step2.txt
@