Here is the visual (YouTube) to help you install a Web Enk theme.

dumb whitespaceOpen your WordPress Dashboard, select Appearance on the left hand column.
Select Theme and then Add Theme. You'll see many different themes to chose from, including at the bottom a large plus symbol to add your own.

Also, on the top can select Upload.
You then can select the theme you've recently purchased by selecting the correct file.
Select Chose File...
And then select the file you've purchased from Web Enk.
Lastly, after the new theme has finished, you select Activate that appears just below the thumbnail.

You're finished!