Well, about getting there - there are couple of methods in the book:
• Using a magical artifact.
• Performing an arcane ritual.
• Finding a willing guide.
• Working with an Adept.
• Discovering one of the original maps to the fae.
• Accidentally stumbling onto the plane.
Also there is a literal hole in Yellowstone.
About "rules are different" - it's not absolutely true either. Mana works the same way, so magicans and adepts stays as they were. Same for physical sams. Deckers and Riggers... that's complicated, deckers can use some kind of living "servers" fae using, and riggers magically became beastmasters. Just as that.
I don't like it though. There is a big chunks of reality very closer to generic shadowrunner to write a book about, I believe. Tirs (yes, one of my players building a character from TIr Tairngire, and I'm trying to get info by bits from all over the books, lending books from friends)? Indians but Siux? Atzlan? Both Americas (USA-Canadian one and Dixie)? Nah. That's a book about mystical metaplan.