Multisite: How to merge a subsite with the main site

Hi,

I have a multisite:

1. example, com= example.com/ar/
2. example.com/es/
3. example.com/en/
4. example.com/ba/

I need to merge 2 and 4 into 1 the main site without loosing the post

Ending with only 2 webs: mainsite and 1 subsite.

1. example, com= example.com/ar/
2. example.com/es/

Any tutorial on how to do this?

I will do it in a new server

Thanks

Irene

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