After downloading theme packages, exact theme package. The file you use to upload is a zip file named sailing. Following these steps below to upload theme via WordPress:
Step 1. Dashboard >> Appearance >> Themes >> Add New.
Step 2. Click Upload Theme button.
Step 3. Browser sailing.zip file in your computer and click Install Now button.
Step 4. Active Sailing.
Step 5. Enable Thim Core to activate the core of Sailing and start importing demo data process.