Alright, The first of these turns off a trigger named "yourtriggername" when you type "triggeroff", the second you type triggeroff [trigger], and it will turn off the trigger with the corresponding name.
You can copy the whole thing (<aliases> to </aliases>) and then click paste on the alias screen and theyll be added.
As seen here:
http://www.gammon.com.au/images/alias_paste.gif
<aliases>
<alias
match="^triggeroff$"
enabled="y"
regexp="y"
send_to="12"
ignore_case="y"
sequence="100"
>
<send>enabletrigger "YourTriggerName", 0</send>
</alias>
<alias
match="^triggeroff (\w+)$"
enabled="y"
regexp="y"
send_to="12"
ignore_case="y"
sequence="100"
>
<send>enabletrigger %1, 0</send>
</alias>
</aliases>
If you want a trigger to do it, then you would have a trigger with the same thing, youd send to : script, and then have that same send string.
If you wanted to manipulate a group, or an alias (turn a group or an alias off) then youd change the send text appropriately (see my last post).
If you want to post less general things, I can show you more definately.