How Do I Convert My Multisite Back to Standard Wordpress?

I've decided to convert my Multisite platform back to standard Wordpress.

Moving forward in my business I realise that it's not needed anymore for the way we are moving forward and we've faced many hassles with it over the last 4 years.

I obviously have a lot of indexed pages which is a concern.

So how do I go about doing this?

Both from a technical perspective and SEO to redirect blog posts?