title: Changing Custom site column to lookup
body: <p>I got thrown in to a situation where the customer has a production enviroment and needs to make some changes without losing data.</p>
  
  <p>One part of the problem is changing a sitecolumn (used in CT, 2-3 lists, and multiple web parts as custom property) from a text field to a lookup.</p>
  
  <p>I have tried to set the schemaxml via powershell and push the changes to the lists. I get errors.
  I have also tried to update the column in the list with lookup schemaxml.
  If i remove the sitecolumn and create a new the webparts stop working, since they need the sitecolumn.</p>
  
  <p>What would be the best solution for solving this?</p>