Updating data in existing survey

You need to be careful when doing this process. Follow these steps.

1. In the Collect Earth in your computer, where you have already imported previously the "older" data; load the original survey and export the data using the option "Tools->Data Import/Export->XML Export->Export data to XML (compressed)"
2. Send the new version of the survey CEP with the new attributes you want to collect to the operators and ask them to open it.
3. Send them the full data that you just exported in your computer and ask them to import it. This way, all of them will start from the same point. To import go to "Tools->Data Import/Export->Import new data from ZIP (compressed XML)". If the operators get the question from Collect Earth if they want to overwrite the previous data (this might happen if they use the same computers they used the first time they collected the data), you can tell the to use the option to overwrite the data.
4. Now the operators (who all have the same full dataset imported in their computer) can start collecting data. BUT! mark the day that they start collecting the data again as you will need it later. Of course, as in the first data collection, you need to assign a CSV to each of one with the plots that they will collect to make sure that there is no overlap.
5. When they are done collecting the data you can ask them to send the data to you so you can again create a unique DB with all the data. VERY IMPORTANT> now you need to tell them to export the data only from the date that they started collecting data again. Use the option Tools->Data Import/Export->Export to XML->Export data to XML (from specific date until present). This will only export the records that the operators re-evaluated instead of the full DB.
6. Import all these new files into your own CE (using the standard import Tools->Data Import/Export->Import new data from ZIP

So yes, the process is a bit clumsy, but if done correctly you can make it work.