I recently wanted to change my default LinkedIn profile from Polish to English and it turned out that such feature does not exists. Even LinkedIn’s help center stated that at this moment there is no such posibility. One can create new, different profiles in other languages, but they are only secondary.
The thing is that the default profile is determined at registration, when I chose Poland it automatically set my default language to Polish.
I work in IT and in an international company, so I wanted to be seen internationally in English.
There is a solution to this. I created a new LinkedIn account with my other e-mail. At registration I chose Ireland, which caused to set my profile to be English. The area in which we reside can be changed later. Then I simply send a request to LinkedIn’s support to merge my old account to my new account. Unfortunately all my work experience was lost, but my connections were preserved, which was the desired outcome. I didn’t want to find all the people again.
After I received from the support that my accounts were merged, I filled my work experience data.