There are two parts of the final step in an open-source project: manufacturing and shipping. The only real trick in finishing your project is to do both of these things as quickly and carefully as possible.
If you can, get someone to help you assemble the project. You can do it assembly-line style, and probably knock it out in an afternoon or two, depending on the numbers. It’s best to start on it as quickly as you can. Sometimes the task of assembly can seem too daunting to start, but it becomes much more manageable once you’ve started.
For shipping, I don’t recommend anything fancier than USPS first-class mail. I’ve shipped out dozens of PCBs, Kits, Components, etc, and have only had one package delayed or lost (we still haven’t determined that it’s actually lost), and that package was sent from the US to Germany. You’ll have to fill out a customs form for each package sent internationally, but other than that, the process is as simple as dropping addressed packages / envelopes off at the post office.