Ok, just want to confirm steps for the quick install - must I just upload files to joomla directory and overide all current files?

you should remove current files, first.

Which current files are you talking about? Only the template files or the whole joomla installation package?

whole joomla installation package

thank you, will do so

I've uploaded the file as you said but it now gives me the following message "Your session write path and the installation directory are not writable. One of them must be writable for the installation to continue."

Which directory must I change and to what?