Trello

From the Trello's website

To export a Trello board follow these simple steps:

1. Open the board you want to import
2. Open the sidebar menu (top-right) from the toolbar
3. Click on the More menu item
4. Click on the Print and export menu item
5. Click on Export as JSON menu item
6. Save the data as a json file (e.g.: trello.json)

In Stacks

Follow these steps to import the trello board json file:

1. Click the + button in the sidebar Documents section
2. Click on the Project menu item

TIP

Or you can use hotkeys to do the same thing by pressing Q followed by P

To select the file to be imported:

1. Click on the Import button in the lower left corner
2. Click on the Trello board menu item
3. Select the JSON file to import

1. Click the Start import button to start the import process