I’ve got concerns about the current basic skin I’m using, I think either I or a developer have changed something. So I was thinking I would just replace it with the one in the install pack.
Download the new install pack and the skins folder is empty 
Where can I find this please.
It is in the var/skins_repository/basic folder.
Technically, you should be able to copy those files over to your store. I've never tried that before though, so I'm not sure.
Another option is to copy those files into a folder called var/skins_repository/basic2
You don't need the admin folder.
Then edit the manifest.ini file that is in that folder and change the name from Basic to Basic2 You can also remove the bit about the admin.
Then just upload – keeping the file structure, var/skins_repository/basic2
Then go into Design => Skin Selector => Select your skin and click install or save or whatever.
Then you'll be working off a new skin called Basic2. This won't overwrite your current files and if you need to switch back, it is super simple.
Better than just copying over your files.
I hope that helps,
Brandon
Thnaks chap that seems to have sorted it.
To be honest I'm about ready to give in on this - moving current site to cs-cart.
I'm now had the licence for over 2 years and it's still not done.