First time I ran the 16x7 wheels at the drags the tech guy said the wheels were good but the spinners had to go. I was ready to go home; it wasn't worth it to me to do all that jacking around to get them off. Another fellow overheard and read my mind: he reached down, grapped one ear of a spinner and BLIP! The spinner was off.
Nice to know. There is an easy leverage angle that works good. He said he was a parts guy at a Ford dealer and they kept having to replace them on the lot cars until someone made the connection and they started having a lot boy harvest them at night and replant them in the morning.
PS: There is some kind of drawer pull or something, available at Home Depot or the like, that is of the correct diameter to keep the spring-loaded fingers from collapsing so the cap will pop out. Installed from the back of the wheel, it makes the caps harder to get off, bu increases the likelihood of wheel damage by a determined thief.
If they are the Ford spinners they just pull straight out. They are spring loaded.