This is only for installing Best-Byte templates.
ALWAYS make a backup of your site before applying new themes and mods etc. Better to be safe than sorry. Upload the folder named catalog to your root directory of your OpenCart installation. There should already be a folder named catalog residing there and no files should be overwritten just the folders with the same names. Go to your Administration and select System then Settings from the drop down menu. Click on Edit for the name of your store then click on Store in the tabs at top. Click on the Template drop down list and select the name of the template. Click Save. If you don't see the name of the template in the drop down list then you did not upload it correctly. Go to your store front and the theme should be displayed. If not clear your cache in your web browser and reload the page.