unLock parameters (Distance or Direction) by keyboard without unchecking the checkbox

Hi.

When I add a civil element (Line---Line Between Points) for an Horizontal gemometry and I press Enter after typing a value then I lock that parameter. OK. But is there any way to unlock again that parameter by keyboard (or shortcut) without having to move the mouse on the checkbox of the Tool Settings window to uncheck it?

And in the case of Profile (using Civil AccuDraw) with Station and Elevation parameters, how can I unlock one of them if "Station" and "Elevation" don´t appear in the Tool Settings window?

Thanks.