I have a 10-year L visa, 60 days each time.

My flight leaves on July 25th but my current 60-day stay is up July 23. From what I`ve read here if I don`t deal with it will I just get a warning for 1st time offense since my overstay is less than 3 days? Or can I pay a 500rmb fine for the 2 days I will be overstaying. Either way sounds like it would be cheaper than taking an extra round trip out and back before July 25th to start another 60 days or paying the fee and rate change the airline will charge to change the flight by 2 days.
I know a lot of people complain about service in China but I find the personnel very cordial and helpful for the most part. I`m wondering if I just go to the main PSB bureau downtown Beijing and bring all my documents and explain the situation if they will just give me the extension without having to go through a long process. After all it is only 48 more hours I need.