Removing Old Dropdown Fields From SharePoint and Harm it Could Cause to Existing Data

I was asked to remove 10 dropdown which the customer has used for 2 years. The problem is that there is 10,000 lines of data consisting of this data. What are the repercussions or harm in removing the dropdown selections and what are some work arounds. I found this article on hiding dropdown fields. Will this be a good solutions.

http://www.balestra.be/2011/05/hide-dropdown-values-from-choice-fields-in-sharepoint-via-jquery.html