Large scale editing - trying to fix national park boundries

Hi All!

I recently noticed that OSM does not include the most recently updated versions of the national parks in utah since our dear leader shrank them significantly. I’ve taken it upon myself to fix this, and I’ve made up a shapefile from the state governments website. I’m fairly new to OSM editing, but from what I can tell, there isn’t really a good tool for really low zoom edits - fixing boundaries this large seems hard. Whats the approach for this?