Hi dannbadila,
1/ Firstly, if you want to install the theme with all the content as our demo, you can download the Quickstart file from your profile
Then Unzip this file into your hosting and install theme.
2/ If you have a Wordpress theme/site running, you can download the GK theme Package.
- Go to the Dashboard > Themes > Upload theme.
- Chose the Gk Theme package then upload into your site.
If you still face their issue, you can let me know the theme that you want to use and provide the FTP account, your site URL (include Username & password) then I will help you install the theme.