Changing store URL to go Live

Hi...
I've been building my store as https://www.mystore.com/zen, but now want to go live, and change the URL to https://www.mystore.com
I've checked the archives, and although this issue has been addressed - I still can't figure out how to make the change. I believe I have to change the session directory in admin to reflect the new folder name - but I get lost at that point.
My current session directory ends with: /html/zen/cache
I have tried deleting 'zen/cache' - but when I try to rename the 'zen' folder on the server '/' - I get an error message.
Can anyone direct me to a step by step approach to changing my URL?
Thanks

This FAQ discusses the process: https://www.zen-cart.com/tutorials/index.php?article=122

I suspect you're running into a problem with step 3 and not knowing how to move files from one directory to another?
(Which FTP program are you using?)

Based on your post, you seem to be indicating that you want to move everything from:
/html/zen/
to:
/html/

To do that, simply use your FTP program to drag-and-drop all the files from your /html/zen/ folder up into your /html/ folder.

All the other steps in the FAQ still apply ... where you have to rename the folder path in the various places.

Dr Byte....
Thanks for your help, and for the link to the tutorial - yes, not sure how to change directories.
I am using a shared hosting service from Gdaddy. FTP is Fetch (mac).
There are only two directories visible when I access the server. The 'stats' folder, and the 'zen' folder I uploaded to. I can see that I need to get the files out of the 'zen' directory to achieve my goal, but no, I don't know how to do that.
Thank you

I haven't used Fetch, but its website suggests that it's a fairly standard FTP client and explicitly lists moving files as one of its functions. Have you tried using it to open the zen folder?

If sorting out how Fetch works proves to be a problem, then you should also be able to move files around by logging in to your Go Daddy hosting account. That will almost certainly have some form of File Manager built in.