I'm trying to edit the "default" file situated at ..

"/etc/apache2/sites-available/default" 

on my small Ubuntu machine running Apache 2.2.8.

I do to be able to enable using .htaccess files. I've downloaded the "default" file and edited it and now i'm attempting to upload it to the server via SFTP. I keep getting permission refused errors.

Can it be because Apache is running and utilizing the file? I'm an admin around the machine and so i would be prepared to have the ability to overwrite the file. Thank you for any assistance.

No it need not be stopped.

Try being able to access the file through ssh, and make certain you can get on with root rights:

sudo nano /etc/apache2/sites-available/default

You'd still have to force-reload Apache after altering the config files, as tux21b recommended inside a comment below:

sudo /etc/init.d/apache2 force-reload