To build one of these printers I’m trying to make it as straight forward as possible.
You will need some skill with basic hand tools and some parts like the aluminum frame and braces are best cut with a circular cutoff saw or possibly a bandsaw.
The troublesome part in some places of the world to get are the connect-it connectors. I’d be happy to supply these if you struggle. You can probably print them and I have seen designs for them online.
The important thing to achieve with the frame is to have it as square as possible, it can be quite hard but the printer quality depends on it. You can adjust some of the printer to compensate.