Follow this steps to install it correctly.

1. Open the "Upload" folder and upload all the content to the root of your forum.
2. If the system ask you to replace, press "yes", it's only custom content.
3. Go to ACP > Templates & Styles > Import a Theme > Select the Plak-theme.xml and press upload.
4. Go to Themes and set Plak as the default theme.

Hope you like it, and enjoy it!

for support thread here
http://www.forumesia.com/thread-plak-res...mybb-theme