How do you disable Change Data Capture on a table or an entire database once it is no longer needed?

You use the sp_cdc_disable_table stored procedure to remove CDC tracking from a specific table, which also drops its associated change table, and use sp_cdc_disable_db to completely remove CDC support from the entire database once no tables are being tracked anymore.

EXEC sys.sp_cdc_disable_table
  @source_schema = N'dbo',
  @source_name = N'Orders',
  @capture_instance = N'dbo_Orders';