Assign activity: yourDT.Columns(0).ColumnName = “New Column Name”
The 0 is the column index, which you have to set for whichever column you want to rename. 0-based index, so if you want to rename the third column you’d use Columns(2)
Or you can reference by column name…
yourDT.Columns(“Old Column Name”).ColumnName = “New Column Name”