Step 1: Log into your hosting space via an FTP software like File Zilla.
Step 2: Unzip the gunstore-vx.x.zip file and use only the extracted Gunstore theme folder
Step 3: Upload the extracted gunstore theme folder onto wp-content > themes folder.
Step 4: Activate the newly installed Gunstore by going to Appearance > Themes, find gunstore and click on “Activate”button