Best way is to start making out and gradually make your way up to grabbing her junk at last you start touch'n nd squeezn her the just slowly remove it but if she jerks back or pushes u back DONT keep...
Tell her she's pretty just stick your hands don her shirt and do what you would do if her shirt was off. Or, unclip her bra (assuming she is wearing one) from the outside of her shirt and when she...
To get a girl to do that you probably have to get to know her better and once you do you might want to talk it over with her. If she is uncomfortable with it don't make her do it.