You can follow below instructions to setup S-Drive for Opportunities.
- Go to https://login.salesforce.com and login to your Salesforce account.
- Go to Setup -> Customize -> Opportunities -> Buttons, Links and Actions. Click Edit on the left of View label.
- Select Override With Visualforce Page and then select OpportunityFilePage [cg_OpportunityFilePage] from the dropdown. Click Save button.
- Go to Opportunities tab and select an opportunity. Scroll to the bottom of the opportunity detail page. You’ll see Opportunity Files section.
- Now you can create folders, upload files etc. to your opportunities using S-Drive.