Aw look at him in his tubes! This happens A LOT! What most people do is remove the tubes and penthouse completely, keep one of the shelves and add a large-ish house at floor level as Elusive mentioned. If you give them a large house that is sat on the substrate and open underneath - they almost always just move in and forget about the tubes (no option if the tubes are removed!). Because they like something that's dark inside. A shoebox house is ideal and easily replaced later. You just cut the base out so it's open underneath, keep the lid as a lift off roof, and cut a hole for a door. I think it works best if the door is at one end of one of the long sides because this means the other end is dark (light doesn't go round corners) and they always choose the darkest place to nest.
The tubes confuse their natural instincts - they do like tubes and tunnels but shorter runs as cage accessories in the cage are better. The other issue is the tubes aren't really big enough and some hamsters grow large and can get stuck.
You'll also need a new wheel

The one that comes with the hamster heaven isn't quite big enough for a Syrian hamster, although fine for a dwarf hamster. A 28cm trixie wheel is popular and fits in that cage (if you take the green shelf out).