There are a few easy ways to change the language of the GSA:

1. If you are working with a remote client, and you don’t want to change the main language of the GSA, you can just open an “incognito window”, log on the GSA Server, and add:

&hl=en

or 

?hl=en

to the end of the URL. Example: 

http://gsa.admin.com/….&hl=en

2. For permanent language change, just change the language of your Internet Explorer.