Component Properties
Double-clicking on a component symbol or placing the mouse over the component and pressing "q" will popup the component properties dialog. This dialog allows various properties of the symbol to to set.
Update all similar components.
If prior to displaying the component properties dialog, more then one of the same symbol has been selected. e.g. by use of ctrl-clicking, then changes made to the current symbol will be copied to all symbols. This allows quick changing of, for example, all of the symbols attached models, or all of the W and L of mosfets at once.