I am currently working on a big upgrade to my Drupal site, this is a live site with active users.

The upgrade is composed of several different parts:
1. Converting the current PHPBB2/3 forum to Drupal forums (Almost done, final glitches and fixes)
2. Create custom themes for the Forum so that it looks and behaves like I want.
3. Desigining a new and improved homepage for the site
4. Remodeling some of the site (navigation improvements, and theme stuff for look and feel of forms etc.)
4. Optional - Converting the current Gallery2 galleries to Drupal Galleries (I don't like the way it's handled, but I have yet to see a clear migration path to move it all to Drupal)

Usually when all I do install a module or change a setting, I just test it on my local machine where I keep a copy of the live site, and then go and do the same thing on the live site. However, this process can't be done on the site itself (no reason to go into details but it has to do with problems with my PHPBB database and not with Drupal), it will be done on my machine.

Question is how would you suggest that I transfer the content to the live site, I see two options:
1. Just reinstall the entire site - i.e. download the whole thing, modify what is needed while the live site is down (so no content is added during this time), and then upload the complete package including droping and creating the DB.
2. I don't know, is there is a better way?

Any advice would be appriciated!