Redoing site on subdomain and moving

hiya,
I have my shop up and running at the moment, but it needs an overhaul.
I have seen some other mods etc that i want to put on, and it also needs updating too.
As i am totally useless at updating (i ALWAYS muck it up and end up having to re-install) can i create a sub directory, install the newest version, install all my mods etc and get it looking right, then move it to where the store is now, or wouldnt that work ?
I am thinking that it probably isnt going to be as easy as that to do, but its work asking isnt it lolol
Many Thanks for reading
Erica xx

Answer to all is Yes...

There is a recommended method so that you also do not have to re-enter your products....

It really is that simple ?
OMG lol
I thought i would be having to alter all kinds of files lolol
what i was going to do with regards to all my products was just download an easy populate list and then reupload .. whats the recommended way ?
OMG i just had a thought (they dont happen often lol) .. if i do what i was gonna do, then i will delete my customers accounts wont i ? doh!
Erica xx

kobra:

Answer to all is Yes...

There is a recommended method so that you also do not have to re-enter your products....

The quick basic answer is;

1. back up the DB of the current live store - (you will do this more than once befor completed)
2. Install Zen Cart in a sub with it'a own DB
3. In phpmyadmin on the newly created DB - drop all the tables - restore your live store backup to this new DB
4. Re-run zc_install and select only the DB upgrade
5. now you have a new install with all of your current data
6. Style and install your new mods etc and check check check and when 120% satisfied that all is functioning correctly prepare to bring this new install to be your live site
7. Place the live site in maint mode > take a new backup of the DB
8. in your new install DB drop all the tables restore the current live DB and re-run zc_install - this is to capture all new orders and customers that have transpired since you last did this.
9. edit the 2 configure.php files for the new store to reflect any changes in location that you might do and bring it up as your live store

The above is the basic method....if you change many of the mods that are installed and these affect the DB you might have to take a bit of care on what you drop the second time around