Uninstalling From Subdomain, Reinstalling to Main Domain

I have WordPress on halphillips.org (hosted by Dreamhost). I’m a newbie, so please forgive my stupid mistakes. Looks like I made two:

1) Not sure how I managed this, but I installed WordPress to the subdomain barbelith.halphillips.org instead of halphillips.org (I’ve worked around this with a redirect).

2) I used the Easy One-Click Install instead of the Advanced method.

I’ve been trying to get FTP access to barbelith.halphillips.org so I can install a plugin, but couldn’t do it, and Dreamhost told me that I can’t get FTP access from the easy install, only the advanced one.

So… I want to get the Advanced version with FTP access, and if possible, I’d also like to install directly to halphillips.org (although I’d settle for the redirect). And ideally, I’d like the pages and posts I have up to transfer over, but if that’s not possible, I can cut and paste.

So… what’s the best way for me to do this?

Can I maybe just do an Advanced install to halphillips.org since there’s nothing there, and then cut-and-paste the old pages/posts, undo the redirect, and pretend the subdomain doesn’t even exist? That seems simple-ish. But I’ve messed up before, and want to make sure I don’t mess up again.

Thanks!