Step 1: Open the word document. On ‘Page Layout’ tab, in ‘Page Setup’ group, choose ‘Margins’ and Margins gallery appears.
Step 2: Choose the margin type that we want to apply.
Step 3: Make our new margin settings the default for our template and each new document based on that template will automatically use the new margin settings
* Choose 'Margins' after we select a new margin, and choose 'Custom Margins'
* In 'Page Setup' dialog box, choose 'Set As Default'