Stating your nationality might be helpful here; a regular schengen visa is 90 days, so I don't know under what circumstances you'd only get a 60 day visa, and I guess that determines if that's strict, or not at all.
Definitely do not wait for your luck, because the likelihood that the immigration officer will notice your overstay, is big. I am not familiar with the Schengen visa rules as I am from a country, that belongs to European Union, but normally the punishments are a warning, a fine or you can be banned from the Schengen Zone. It is all up to the officer, what punishment he/she will give you (there are definitely some rules too, but it depends very much on the situation and the officer). They may just give you a warning (if nothing else like that has never happened to you before, so you have never overstayed any visas; if you are able to explain that it happened by accident, that you didn't plan to overstay), but you may also have to pay a fee (I read somewhere, that the fee may be up to 700 euros) or you can be banned from the Schengen Zone (Again I read that you can be banned for one year or more and you can also be given a lifetime ban). Even if the officer doesn't notice your overstay in Milan, Italy (where you will be leaving the Schengen Zone), you may have problems reentering the Schengen Zone: they want to make sure that you haven't overstayed the Schengen Zone as if you have, you are more likely to do that again and the officer will check your last time, when you entered the Schengen Zone and for how long you stayed. The point of this long story is that there is no point to hope that they will just let you through as you will be caught anyway and you don't want that this 5 day overstay will infringe your future trips to the Schengen Zone, right? Now, what should you do? Again, being a resident of EU, I am not familiar with all the rules and applications of Schengen Zone. But I am pretty sure that the rules vary a bit by nationality (so by the country you come from), so the best advise I can give you is to contact the embassy and ask for options. Maybe they can extend your visa, maybe not. I really don't know.
So I hope this comment helped you and have a nice and safe trip!
im indonesian btw.
and i just ask an officer in my embassy and they say there'll be no way i can extend my visa. because it's a visit visa. is there anyone out there have been trough this?
Can't you reschedule your departure? Better and cheaper than a fine or a ban.