how to change default directory by htaccess file

put this code there and get what do you want

DirectoryIndex filename.html
DirectoryIndex filename.html index.cgi default.htm
Redirect /olddirectory/oldfile.html

htaccess, which is probably the most effective, considering the minimal amount of work required to do it.
htaccess uses redirect to look for any request for a specific

and put there

Easy htaccess tutorials