Migrating 130 WP sites to Multisite... step by step...

I have a project where we are considering to migrate 130 WP sites, each with about 800 existing posts/pages plus about 25 with static html pages to a multisite installation. All the same owner.

Would this be a monumental task for a semi-newbie?

Are there step-by-step instructions anywhere to be found for doing a migration like that?