"Read-only file system" remount problem.

[AC Question]

I'm using Huawei Y6 (SCL-L01). I've got root by KingRoot App and I'm going to replace a bootanimation.zip file but when I'm trying to delete this file the phone says: "Can't delete file... "Read-only file system"". I was trying by adb but It's still doesn't work.

Sorry for my bad English but I'm from Poland