I don't own it, or have any experience with it, but I assume it has internal fuses that are replaceable, the external one does not need replaced because the unit will not power on without that one. Be sure that you replace the fuse with the same rated fuse. Also, if you do change the fuses don't put the cover back on until you are certain it will perform in a stable manner. If the fuse blows as soon as it is turned on there is a problem. If something goes up in smoke there is a problem. In this case you must disconnect the receiver from power immediately, as it may not have any protection beyond the fuses. If the current fuses are already blown there is a very good chance that the next one will blow and smoke will emit from the problem, or the first problem in the circuit.
I hope for your sake the fuse does not blow and it works perfectly, but plan for the worst. Work safe and smart, meaning no hands inside the receiver once it is plugged it, and use a switched outlet or power strip with a switch that can quickly and safely disconnect power from the receiver if there are any problems. Do not connect any other devices to the receiver (speakers, sources) until you know it isn't going to go up in flames. I always test the output with a junk speaker or speaker driver to avoid damaging my good components.
Good luck.