Venesi City: can't navigate the gym!

[ISNorden]

I've just collected badge #5 in a new game, and am now planning a trip to Venesi City.  Love the items and NPCs...love 90% of the architecture...love the atmosphere overall.  But if there's one thing I hate about Venesi City, it's the same thing I hate in other Pokémon games.

Puzzle-floor gyms.  Especially slippery puzzle-floor gyms.

I've searched Google and YouTube for help, but the video solutions have been too fast to follow.  Could someone please give me some step-by-step directions (in words or a diagram) for navigating Venesi City Gym?  Thank you very much!