HaloMods "Classic" Read-only Archive

For a project im working on i want to change the map deathisland by getting rid of the canyon on the side. I checked the tutorials but i still have no idea how to edit the map like i want to.

You can't edit map geometry in PC. That is possible in the HEK, but then you would have to import the model for Death Island, edit it, RE-texture it (this takes a long long long time to get it perfect), export, compile, place, etc.

Yes, you cant just edit it like you want. The map file has been designed to take in a set amount of vertecies, so if you delete or add any, the file will crash because the file is corrupt.