1. Sign in to Joist from a computer at my.joistapp.com and head over to the Items section.
2. Use the Import/Export button to save a CSV file of your items list to your computer.
3. Open that CSV file in a spreadsheet application like MS Excel, Apple Numbers or Google Sheets and delete the rightmost column from the spreadsheet -- this is the column containing a series of random numbers in each cell. Save the file as a CSV.
4. Now you can sign in to the other Joist account and use the Import/Export button to import that CSV -- that's it!