Nelji hills trek

We are a group of 10 people planning to visit coorg in the first week of October. We are planning to go to nelji hills. But we have a few queries regarding it

1. Where exactly is this located?

2. What's the difficulty?

3. How long will it take?

4. What's the preferred mode of transport to reach there?

It would be very helpful if you all could help us out with this. Thank you!