Walkthrough

1. For completing this request, you can get Access to the Central Island as a reward.
2. Rebuild the Huge Building Walkthrough
3. Tinkmaster will ask you to help them reach the giant tower on the nearby island. You can either stack blocks to create a bridge between the two islands or build a Lift Platform at the top to connect them. | | The latter is highly recommended, as the other side already has a Lift Platform that will link the islands together.
4. Ride the platform and head to the building. Help Tinkmaster investigate the area by climbing each floor through the back exit.
5. After exploring, return to the entrance and speak with Professor Tangrowth to complete the request. This will also unlock the next quest, Rebuild the Huge Building.

Walkthrough source: Game8.