Hi guys, i was shooting an event today for the first time with my Nikon 70-200 and i've got 1 huge burning question. How do you guys change lens fast with that lens and let's say a tamron 28-75?? I cant do it the way i normally do it which is to hold 1 lens with my index finger and thumb and remove the lens on my camera using my remaining 3 fingers! The lens is simply too heavy! In fact, i can barely change it without needing a surface to put the lens on. help pls!