Change textstring to multiple text string or richtexteditor

Just copy the data in dataNvarchar to dataNText (or vice-versa) in the table cmsPropertyData with the right  propertytypeid to have the content on the property in umbraco.

Force Republish umbraco

http://siteUrl/Umbraco/dialogs/republish.aspx?xml=true

Source:
http://our.umbraco.org/wiki/reference/api-cheatsheet/publishing-and-republishing

Change Nodes Templates

select * from cmsDocument where nodeid in (select id from umbracoNode where parentId = 1207) and  newest = 1

update cmsDocument set templateid = 8663 where nodeid in (select id from umbracoNode where parentId = 1207 ) and  newest = 1