The best way to ban an avatar on your own land is to right click on them and select Freeze from the pie menu - this gives you 30 seconds in which they cannot move or talk - time to take a deep breath - take a snapshot for evidence - and then chose Eject and Ban from the pie menu. It is also a good idea to take a copy of the chat from just before the incident to when you Freeze them. This is also evidence that Linden Labs can use to ban someone from SL.
|Freeze step 1||Freeze step 2|
|Eject step 1||Eject step 2|