Back-up and update assistance required.

Good day,
I need some urgent assistance with the classifieds theme i currently have.
At the moment I need to move away from my current ISP to a new one, but the original ISP refuse to assist with a back-up for the new ISP.
I managed to load the original theme version 7.0 onto one of my other sites to see if i can re-load the theme onto a new site.
my problem is that at the moment the site is running on version 8.3. if i download the zip file from the members are, then only parts of the theme are downloaded. (not too sure what the latest version is)
can somebody please assist me on how to update the theme from version 7.0 to the latest version.
with regards to a back-up, i can copy all the changes that were made to the current site with screen shots and then re-enter everything once i manged to change to the new ISP and managed to update to the latest version.
currently i do not have any classifieds on the site, i had to wait until i move from my current ISP to the new one.
Assistance regarding this would be appreciated.
thank you all in advance.