1. Log in to your Wordpress dashboard 

2. Media > Add Media

3. Drag and drop your image file

4. Click "Edit"

5. Copy the URL of the image

6. Log into Magento Admin

7. System > Configuration

8. "Design" (left sidebar)

9. Scroll down to miscellaneous scripts

10. Replace the URL's with the new images that you uploaded in Wordpress

11. Save

12. Clear Cache