You may have seen forums discussing OpenWrt for the HG658 v2. While theoretically possible, it is for average users.
Please note that updating the firmware on your HG658 V2 router may void its warranty. Additionally, if you encounter any issues during the update process, you may need to reset your router to its factory settings. hg658 v2 firmware download
Huawei has removed many older router firmwares from their global consumer site. However, you can check: You may have seen forums discussing OpenWrt for the HG658 v2