It’s pretty easy and straightforward to uninstall the contactic plugin.
Navigate to the “Plugins” > “Installed Plugins” in the wordpress admin, find the plugin called Contactic, and click on “Deactivate“
You will then be able to see the “Delete” button. The plugin will be uninstalled and removed by clicking on this button.
Important note:By default your data (submitted forms) and the Contactic database will be kept while deleting the plugin, unless you have configured the plugin to delete your data, as described bellow.
If you explicitly want to erase the data while deleting the plugin, be sure that the corresponding option “delete database on uninstall” is set to true, in “Contactic” > “Options“, System tab.