TEMPLATE_DIR = Joomla! ROOT/templates/YOUR_DEFAULT_TEMPLATE

1. GO TO - "TEMPLATE_DIR/custom" using an FTP client.

2. COPY - ALL FOLDERS to "TEMPLATE_DIR/custom" directory.

3. OPEN - "custom.scss" file from "TEMPLATE_DIR/custom/scss" directory.
   (If it doesn't exist, create one on "TEMPLATE_DIR/custom/scss/" directory.)

4. ADD -  
	@import "dependencies";
   on top op "custom.scss" file IF ALREADY DOESN'T EXIST.

5. ADD -  
	@import "gp_accordion1";
   on "custom.scss" file under @import "dependencies";
6. LOGIN - to your website admin -> GO TO Gantry Admin -> Recompile CSS.