Working in Test Mode before uploading
I am working on a project with a colleague who is in another country. She has downloaded all files of her site onto her hosts server. What she wants me to do is access CSS files and change the look and feel of her site to her company branding.
I have the FTP details and Control Panel details to access these files but what I'm unsure of is the best method of me to play around with the design without the live site being modified. I need to work in a test environment, then send files to my colleague and once she's happy then we upload the files to the live site.
Hope I've explained myself well enough. Any help with this would be great.