Warning: Make a backup first

If you have not visited the cells that this map uses, you can just add it to your save.

If you have visited those cells before, follow this guide:

1. Go to your save folder C:\Users\"username"\Zomboid\Saves
   
2. Remove map_XXX_YYYY.bin files that go from "map_800_740.bin" to "map_886_780.bin".
   
3. Delete the chunk files (this will reload loot) "chunkdata_27_25.bin", "chunkdata_27_26.bin", "chunkdata_27_27.bin", "chunkdata_28_25.bin", "chunkdata_28_26.bin", "chunkdata_28_27.bin", "chunkdata_29_25.bin", "chunkdata_29_26.bin", "chunkdata_29_27.bin".
   
4. Delete the zombie population files (this will reset zombie spawn) "zpop_27_25.bin", "zpop_27_26.bin", "zpop_27_27.bin", "zpop_28_25.bin", "zpop_28_26.bin", "zpop_28_27.bin", "zpop_29_25.bin", "zpop_29_26.bin", "zpop_29_27.bin".

This can be made for Singleplayer and Multiplayer aswell. Tutorial extracted from:

Originally posted by EPD:

"WIPE PART OF MAP":

Warning: That part of map will be removed, cleansed, wiped out. No bases, no loot, no vehicles. It will LOAD again like you never visited it before.