How to clean, scale or orient the point cloud using Cloud Compare 

Hi! Thank you very much! Could you help me with the following: 1 need to cassify points of a LAZ file so that trees, water, ground, building atc are defined in their clacces within LAZ file. I know you can classify points in cloud compare, but how to save this classification within LAZ of how to substact only points of needed class and save them separately useing CloudCompare?