Any plugin that has not been enabled for the entire network on WordPress Multisite can be activated on an individual site as follows:
1. Locate the site you want to enable specific plugin on by searching for the site using Sites > All Sites in the Network Admin dashboard
2. Once you have located the site click on Dashboard (hovering your mouse over the domain name brings up the action menu)
3. Go to the plugins page in the Site Admin dashboard.
4. Click on Activate below the desired plugin.
5. Some of the plugins provide an administration screen where you can set options specific to that plugin.
- Most are located in the Settings menu in the Site Admin dashboard however they can be located under a range of menu items. Askimet, for example, is located in the Plugins menu.
- Some plugins also add widgets to your available widget area which you can access via Appearance > Widgets
6. To switch off a plugin click Deactivate