Remove missleading installation information

Documentation/Installation/Index.rst

@@ -7,15 +7,6 @@ Installation
 ============
 
 
-Download via Extension Manager
-==============================
-
-In the TYPO3 Backend go to Admin Tools > Extensions. Change in the dropdown on
-the top left to 'Get Extensions', enter the extension key 'ew_llxml2xliff' in the
-text field below the headline 'Get Extensions' and hit go. In the result list
-install the extension by hitting the action for that.
-
-
 Download via Composer
 =====================