To customize template with stylesheets:

1. Go to Manage > Visualizers > Click on edit icon of your visualizer
2. Go to Editors > Click Stylesheets tab
3. Click New Stylesheet button > Specify your stylesheet path
4. Specify inline styles in Inline Shylesheet field

To customize template with scripts: 

1. Go to Manage > Visualizers > Click on edit icon of your visualizer
2. Go to Editors > Click Scripts tab
3. Click New Script button > Specify your script path
4. Specify inline script in Inline Script field