Open multisite in 2nd site

I have a 2 language site, I designed it as english being 1st site and German being 2nd site. I now need to swop it around so it opens in Greman Site.
Site was built in wordpress.de
2nd site is wordpress.de/de.
I am not sure how to open in the wordpress.de/de as my FTP only has
1st site as option to point to.
Any advise would be greatly appreciated.
Site is
German version which is site to is accessed by language switcher.