I have entered a few trailhead parking areas (less than 60) into OSM over the last few months, and just realized that I had not included the elevation data, which is quite valuable in this context.
I have retrieved my data (Xapi) and am about to add the elevations, but before I do that I would like to know how I get this data back into the database. If I upload the modified file from josm, will the modified nodes overwrite the originals, or will I have duplicates?
Any further advice on this much appreciated