Required tools: MC Certificate Version , BE , prev auditor , \Take QQ 2011 as an example: first change the suffix of the QQ file you want to modify to .zip, then open QQ.zip with BE, search for drawChar, you will find several classes, usually the smallest one is it, 1.1K: lm.class. Then open lm.class in BE, open the method , as follows\ 10 iconst_0\ 11 iconst_0\ 12 bipush 8\ Modify the second iconst_0, which is line 11 (this is for modifying italic/bold/underline); modify bipush 8, which is line 12 (this is for modifying font size). The following are reference values.\ iconst_0 = regular\ 1 = bold\ 2 = italic\ 4 = underline\ bipush 0 = medium font\ 8 = small font\ 16 = large font\ After modification, save, check with class auditor, replace in MC, compression level 9