Migrate SCCM 2303 to MECM 2403

Hi

we have an ancient SCCM 2303 and since it's using SQL 13.0.4604 (2016 of some kind), and it makes it vulnerable. so i've been asked to make things happen. meaning i need my sccm to go from 2303 to latest mecm 2403. i understand it's to be done by setting up a new server with clean mecm, and import old data.

is there a step by step guide that describes how to a) export data from old instance, and b) import data to new instance?

i read some data like certificates and passwords maybe will get lost i don't care much about that. it's to enter/import in a couple of minutes... also the configuration manager (sccm & mecm) modifies/grows on the active directory structure. so concern is if the old did different modifications/wordings/whatever than the new version or it's a smooth, relatively easy/straight forward migration?

i'm sure i'm not the only one. so must be a very clear 1-2-3 explanation/method. i prefer written instead of video though.

thanks

Gabe

my other thought is to set up a "secondary" server running mecm 2403 and sync data from sccm 2303 then make mecm primary, and shut down sccm. is that doable and if so, then how?