For the second part you are filling one of the valid values (in fact it will do all of them, but repeatedly change the same record), and it probably doesn't matter to you which of the valid ones are used - but you may know different. What wild_bill posted looks fine to me.

The third part will add the rows for the other cities. What wild_bill posted is almost right, you should just remove ldc_zip_ik (from the field list and the Select list).