WhatsApp - Merge chat history from two contacts

[Shadow128]

Hi there,

I've several contacts, who changed their phone number and now I've two chat historys.
So I want to merge both historys to the new number.

I know from the past there is a possibility to edit the database with SQLiteBrowser, but I can't remember the commands.
Or maybe there is a simple tool, which can automatically change all related stuff from old number to new number?

Hope that maybe someone can help me


Thanks and best regards,
Shadow128