Open the Word document
Go to the Design tab
Select Watermark
Click Custom Watermark
Choose Picture Watermark
Click Select Picture
Choose the image you want
Click Insert
Adjust scale if needed
Click OK
Save the document
Open the Word document
Go to the Design tab
Select Watermark
Click Custom Watermark
Choose Picture Watermark
Click Select Picture
Choose the image you want
Click Insert
Adjust scale if needed
Click OK
Save the document