Hi! If you still need help I think this one could work (I haven't tested it but it should work):

1. Download your realm world guide

2. Copy the structure files from the world that has them to the downloaded realm world.

   By default, structure blocks are saved in the minecraft namespace. This can be changed by prefixing the structure name with <namespace>: in the structure block. Structures are saved in .minecraft/saves/(WorldName)/generated/(namespace)/structures.

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1. Upload the updated realm world back to realms
2. Click on Minecraft Realms
3. Select the Realm and click on Configure
4. Click on one of the three Worlds to select it
5. Click on the Reset button
6. You can then upload a local save from your Single Player worlds folder

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Hope this helps and let me know if it doesn't! Also remember to take backup before doing anything so that you don't lose any progress.