In the PcbDoc, manually select all the items of interest (ex. reference designators) with the 'Shift key" and left mouse button, then got to 'View' and 'Object Inspector'. The items you selected will appear in the drop down dialog, and give you the option of editing the parameters.
I'm hoping they add the AD "Find Similar" select option in the next release, which does a global select of any parameters you specify, then edit as above with the Object Inspector. Fast and easy.