How to reset long term fuel trims?

[Hulkss]

For E38, Select DVT, then Fuel System, and then click on Fuel Trim Reset

Thanks, after specifying the target controller (Gen IV V8, V6 E38 ECM) this looks like it will work. Have not tried it yet.
Should this be done with the engine running, or just with ignition on, or doesn't it matter?

[joecar]

Doesn't matter.