Replacing a media player in a web script - How to open a .js file

I’d like to replace the player in a small web page video player script.
The script has a swfobject.js file and it’s my understanding that it may be just a matter of uploading the new player swf to my webspace and then editing the js to point to the new player. I don’t know how to open a .js file, and this may be too small of a request for a freelancer. Can someone help me with this? Any guidance will be appreciated.

You never need to edit the swfobject.js file, all parameters that affect it’s operation, and the source of the embedded swf, are controlled in the page html and within inline script in the html