Excel macro - numbering rows based on logic

my Excel macro skills won't get me to the desired result, so I'll have to ask you guys :-)

On the left side of below image you see the current state of my Excel sheet.

Note: it's all about the numbering.

At the moment the numbering is needed to process the sheet. However in a newer version the sheet will look like the right side of the image.

For the new version to work, I'm looking for a macro that will remove the numbers and output the right side of the image.

However if I need to go back to the old version for some reason, I would also like to know how to put the numbering back in there.

Hope you can help me out here.

Thank you.