Click on “Settings” in the upper right
2. Click on “Page Layout” in “Build or Application Settings” > “Customize” > “Account Administrator”
3. Click on “Edit” next to “Contact Layout” or “Account Administrator Layout”
4. Select “Visualforce Page” from the layout panel, then drag and drop “Contact Documents” to the “Detailed Information” section on the bottom.
(Minimum Height: 350px)
5. Click on “Save” in the layout panel