How to change primary language of the website?

[SEO_MediaInno]

Problem: there is a domain.com which primary language is Lithuanian, we want to switch it to English. The English content is on the website fully translated under domain.com/en/english-url.

Question: How do i switch English content to domain.com while moving the Lithuanian one to domain.com/lt/lithuanian-url

The purpose of course is NOT to loose neither English nor Lithuanian organic traffic

Possible solution: the only solution I though of is to 301 English /en urls to domain.com ant to 301 the Lithuanian domain.com urls to /lt. Is that everything I should do or is there some other meta tags, server side or other stuff i should be worried about?

[SEO_MediaInno]

So basically the same that I thought off... thanks for your response Irving.

[irvingw]

if english is the sites main language i would put that in the root, not in a en folder

since the LI language pages are under the main root, create a /li/ folder and then 301 redirect the root domain urls to these new ones.

then create new root domain urls for the english version, they need to be different urls than the old LI root domain urls which won't be a problem.