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Its "just" a Launch with a combined Relaunch You could use both checklist like https://moz.com/blog/10-things-relaunch-your-website for the relaunch part. Here you could find Redirects and so on. Additional you could use https://moz.com/blog/starting-over-part-1-a-prelaunch-checklist for the Launch Part (Domain, Server, CMS, ...). Dont forget part 2 and 3 https://moz.com/blog/starting-over-part-2-launch, https://moz.com/blog/starting-over-part-3-optimize. Depands on the website, but normally it's not a one man job - a team with a lot of knowledge (ideal in relaunch) should support that job.