To manage a snippet, you have three options which are view, edit and deactivate.
Path: Space > Ellipse Icon > Settings > Snippets
Select your desired space to see the Ellipse Icon.
Manage the snippet by clicking the ellipse icon and click View to see the details.
Here you can view the snippet details.
Next for edit, click on the Edit option.
Edit the snippet name and content and click the Save Changes button.
For deactivating just click on the Deactivate option.