You can edit or delete keyword groups in the SEO Campaign module. To edit your groups, click on the pencil icon in the upper left corner.
In the pop-up window, you can:
rename a group, by clicking on its name;
delete a group, by clicking on 'x';
edit the rules (for smart groups) by clicking on the settings wheel.
Deleting a group does not delete its keywords. They will continue to be monitored in other groups (if they had been previously added there) or in an automatically generated group called Ungrouped.
Here's a video to guide you through the main available metrics in your SEO Campaign: