Overwriting Existing WP site with local site

I have rebuilt my site from scratch with a new theme. Some of the content is the same, some is different. For the same content, I have kept the url structure identical. When I say ‘different’, I mean that some of my existing WP site pages, I have chosen not to include in the local site.

My question is this – what would be the easiest way to completely overwrite my existing WP site (online at goldhatphotography) with my MAMP created local install, ensuring that no ‘mess’ is left afterwards.

I know there are numerous resources online that describe getting a local WP install online, but none of them deal with overwriting an existing WP install.

Please help!
Thank you,
Mark