How can I change block entity data at specified position?

BlockState bs = level.getBlockState(pos);
BaseEntityBlock beb = (BaseEntityBlock) bs.getBlock();
BlockEntity be = beb.newBlockEntity(to, bs);
CompoundTag nbt_to = be.serializeNBT();
for (String key : nbt_from.getAllKeys()) {
	if (key != "id" && key != "x" && key != "y" && key != "z") {
		nbt_src.put(key, nbt.get(key));
	}
}
be.deserializeNBT(nbt_to);

nbt_from is nbt data which I want to copy to BE at position pos

How?

get blockstate from level and position
verify that it's a kind of block you need (for example furnace)
get block entity from level and position (do not make new, get from level)
cast to its specific type and access fields directly (burntime = 0 for example)

ok, thank you