You would have to reinstall to get rid of the patch. The games should remain in place (when uninstalling you will be asked if you want to keep them or not), but to be safe it would be best to copy or zip them to another location first. Unfortunately, though, games saved under the latest 1.34 version of DD can not be opened in the unpatched version, so you would have to start over or revert to a save made before the patch was installed.
If you just want to use the charm pane exploit (which was fixed in the patch), there are better and safer ways to do the same thing in the patched game. see
charming a weapon or equipment
