There are two ways: First, you can download a pea pods mobile assistant from your mobile phone, search WeChat-Open-Version History, and click Version History to download the version you want directly. Second, use the computer to find WeChat official website, which contains the history of WeChat versions, and then find the corresponding version of your mobile phone system and download it to your mobile phone.

I've done this before. Personally, I think the new version is not as good as the old one, so I still use the old one. I hope it helps you!