Need to change to 29.97 drop frame

So I know that you need to settle on the framerate before you add media into the media pool, but what if you simply want to change from non-drop frame to drop frame timecode for all of your timelines? Right now I have two rough cuts completed in 29.97 non-drop, but I need to change over to drop frame 29.97. Here's what I have tried:
- Select "use drop frame timecode" in the master project setting (setting is greyed-out, so no luck there)
- Create new 29.97 drop frame project, and copy and paste timelines to new project (ERROR: Current project frame rate does not match that of copied timelines from the media pool.)
- Copy contents of the timeline from non-drop project into a new timeline in the drop frame project (ERROR: Current project frame rate does not match that of copied items from the timeline.)
- Export XML, and import into new 29.97 drop frame project (same error)

Any other workarounds for this?

So I know that you need to settle on the framerate before you add media into the media pool, but what if you simply want to change from non-drop frame to drop frame timecode for all of your timelines? Right now I have two rough cuts completed in 29.97 non-drop, but I need to change over to drop frame 29.97. Here's what I have tried:
- Select "use drop frame timecode" in the master project setting (setting is greyed-out, so no luck there)
- Create new 29.97 drop frame project, and copy and paste timelines to new project (ERROR: Current project frame rate does not match that of copied timelines from the media pool.)
- Copy contents of the timeline from non-drop project into a new timeline in the drop frame project (ERROR: Current project frame rate does not match that of copied items from the timeline.)
- Export XML, and import into new 29.97 drop frame project (same error)

Any other workarounds for this?

DR 12.5 has a new feature that allows to change this in the Delivery page. If you are running previous version of DR 12.5, this it's not possible without going to some workaround mentioned here in another similar thread.

Thanks. I did check the deliver page but did not see a drop frame option. I am in the latest version of 12.5. I will poke around again tomorrow.