I just finished my second Chinese language site, also a copy of an original English language site I developed.
Someone translated all of the content and my reading comprehension of Chinese is good enough to know where to put what, so that part wasn’t much of a problem. In fact, it was mostly a straightforward process. I created a new directory and installed a backup of the English language site and then just cut and pasted the Chinese language content to replace everything.
The hassles were in messing with the css style sheet to make the top menu link show up in white instead of green and then a bear of an issue with IE. Everything looked great in Firefox but IE didn’t know how to read my site, even though I told it the character set was simplified Chinese. I finally managed to hack to code and took out the php parts and replaced it with html code in a few places and now it works. It was a real pain though.