Cannot change the permissions of .htaccess

So I want to remove the .html extension from the , I want to turn /index.html to /index

so I have to edit htaccess in the root directory
to edit htaccess I have to change the permissions of it , the default permissions (the ones that I have) are r–r–r-- and I have to change them to rw-r–r–

well, when I change them I get this:

Changing item permissions failed with error: Error during FTP change permissions, file not found: “/.htaccess”.

Can someone help me?

Is that the .htaccess file with the big DO NOT EDIT at the top? If so, DONT EDIT IT, you need to create a new one in the /htdocs folder instead.