Download wsp-package and place it to one of the servers in your Sharepoint 2013 farm. Run Sharepoint 2013 Management Shell as administrator:
Print Add-SPSolution <path to wsp-package> :
Open Central Administration as administrator → System Settings → Manage farm solutions. Select plumsail.orgchart.wsp and press Deploy Solution link:
Go to your application. Select Site Settings item in the root of the site collection. Choose Site collection features in Site Collection Administration section:
Activate Plumsail Org Chart feature.