FTP & SFTP. Double-click the disk image (.dmg) for Fugu. Click Agree on the license agreement to complete the expansion of the disk image. The Fugu virtual disk will mount onto your desktop. Double click the virtual disk,to open a window with the Fugu program in it. Please copy the Fugu program to your hard drive, preferably to the Applications folder. In the Applications folder, open the Fugu application by double-clicking on its icon.