Press Alt-F2 to open the run dialog. Type the following into the text box and click “Run”.
The window that opens allows you to copy and paste new font files to install them.
This is the another way to install font using command line,
sudo gksu nautilus /usr/share/fonts/truetype/
Then you should get new GUI window and create a new folder with appropriate name and copy your font into it. Close the widow and come back to command line.
sudo fc-cache -f -v
Thats all about the installation...