What's the file extension on the files and how did you get them? Are they download content for the download version of Movie Edit Pro or are these files from Catooh? If they're executable files, you'd just have to run them (while Movie Edit Pro is not running) and they will install the relevant content files into the correct locations automatically. You won't have to drop the installers into a specific directory. After that, start up Movie Edit Pro and you will find the new items in the appropriate program sections.

If these are MTP files from Catooh, you need to install them from within Movie Edit Pro. Just use the built-in file browser to browse to the file's location and double-click them. The installation will then take place automatically.

I hope this helps.