How to unzip a multipart (spanned) ZIP on Linux?

I need to upload a 400mb file to my web server, but I'm limited to 200mb uploads. My host suggested I use a spanned archive, which I've never done on Linux. I created a test in its own folder, zipping up a PDF into test.zip.001, .002, and .003. How do I go about unzipping it? Do I need to join them first? Please note that I'd be just as happy using 7z as I am using ZIP formats. If this makes any difference to the outcome.