Trying to find an easy way to describe what you need to do but failing miserably!
1. Copy the folders you want to move from your user account on the C: drive to the HDD. These will probably be: My Music, Downloads, Pictures etc.
2. Go to the start menu and right click on the folder you want to change the location of.
3. Click on the Properties line in the popup window.
4. In the window that opens click on the "include a folder..." button and navigate to the folder you copied onto the HDD.
5. Once you have added the folder left click on it and then click the "Set save location" button.
6. Repeat steps 2 - 5 for each of the folders you want to relocate.
Once you have set the default location for your folders you will need to alter the default settings for your web browser and other programs to save things to the same folders on the HDD rather than the SSD.
After you are sure everything has been copied to the HDD, you can safely delete the contents of the folders to free up space but I wouldn't delete the folders themselves as, when empty, they do not take up any real space but it can save you from problems if you forget to change the default save location in some of your programs.
