To replace the 700 interface fuse, use a screwdriver to pry open the fuse tray. The fuse tray is located directly below where the power cord plugs into the interface and has an extra fuse in it. The fuse furthest from the interface box is the replacement. Remove the old fuse and put in the replacement fuse.
If you have already used the replacement fuse, the fuse for the CI-6565A 700 interface is 5 by 20 mm, Slo-Blow, 250V, 0.2 A. It is available from PASCO as part number 530-026.