If you remove an access-list from the configuration while it's applied to an interface, the interface will pass ALL traffic as if there were no ACL applied. ___HOWEVER___ if you are doing so in order to put in place a rewritten ACL, be aware you will disrupt traffic passing over that interface. As soon as you've entered the first line of the new ACL, it will be a working one-line ACL, WITH A DEFAULT DENY AT THE END. This will get you into trouble, so it's recommended that you either remove the access-group statement from the interface while you're working or create a new ACL and switch the interface over to the new ACL.
