import com.sun.xml.internal.ws.org.objectweb.asm.*; class Asmator { static byte[] fixup(byte[] buf) throws java.io.IOException { ClassReader cr = new ClassReader(buf); ClassWriter cw = new ClassWriter(0) { public MethodVisitor visitMethod( final int access, final String name, final String desc, final String signature, final String[] exceptions) { MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions); if (mv == null) return null; if (name.equals("callme")) { // make receiver go dead! mv.visitInsn(Opcodes.ACONST_NULL); mv.visitVarInsn(Opcodes.ASTORE, 0); } return mv; } }; cr.accept(cw, 0); return cw.toByteArray(); } }