Could somebody help me to revert a changset ?

I made a mistake and I am unable to revert the changeset. The changeset is 52489487. After duplicating a relation in JOSM, it appears that all ways and nodes are also duplicated two kilometers in the south. I tried to revert the changeset with the plugin reverter, but I got an error. The error is submitted here : https://josm.openstreetmap.de/ticket/15373#ticket

I am now looking for help to correct this mistake. Thanks.