Hi okyere,
how many unique numbers like 100003 do you have?
The first row of the workflow in the linked video is a basic chain of textprocessing nodes. Documents are red/parsed or created and peprocessed by various preprocessing node. For information about the textprocessing nodes please see:
https://tech.knime.org/knime-text-processing
here you can find a online documentation:
https://tech.knime.org/documentation-3
and here example workflows:
https://tech.knime.org/examples
Cheers, Kilian