Archive consists of update.zip, firmware for flashing via fastboot with necessary scripts and instruction in Chinese.
How to back to 20S firmware from bootable 26S:
1. Install via stock recovery update.zip from archive. Your new firmware will be 001D.
2. Unlock bootlader.
3. Install via fastboot 020S firmware by open .bat file with chinese symbols.
4. Now you are on stock root-friendly multilang firmware without chinese apps.
P.S. Because of little information about this phone, please, write here about successful and unsuccessful attempts