How to change value of drop-down field?

We have defined a product and via TM Extra Product Options, have created a Select Box with a number of options. We would like to change the options, but we have already ordered several products. Thus, if were to simply change the form, the existing orders would not be findable (since we have a search function that uses the values from the Select Box).

I tried using Search Replace DB (see https://interconnectit.com/products/search-and-replace-for-wordpress-databases/), and this reported six instances (of one particular string) that would be replaced. However, when I loaded the database into a text editor, I found 131 instances that would need to be replaced, thus the script will not work. Doing this manually is not a viable option – to many opportunities to make a mistake.

Is there a way to globally change the value in the Search Box and in all existing orders?