Sounds like you are using Data Prep Studio. If you open your workspace and look at the Prep Data tab, you should see your table that is loaded on the left side. If you left click the drop down arrow, you will see several options. The one you are looking for is "Edit File Path"
Select it and browse to the new database that you want to point to.
Ok. Just want to throw out the obvious one to reconfigure the ODBC entry, but I am going to guess you have other tables or workspaces that use the same entry so that probably won't work. The second one would be to start a new workspace, but export the existing change list from the current one and then import it in the new workspace.