I'm finding that babies aren't too hard to pop. Especially if they are fat and well hydrated (like right when they come out of the egg). Be careful not to bend the spine or push too hard. I just use one thumb to pull the vent scale gently forward and use the other starting a good ways back and rolling toward the vent. On the males you see red tubes pop out and on females smaller white tapering and hooked horn like structures.
Each of the eggs from het X het has an independent 25% chance of being homozygous. With a 6 egg clutch your chance of having at least one homozygous is 1 - .75^6 = 82.2%. The 75% is the chance each has of not being homozygous. Razing .75 to the number of eggs gives you the cumulative odds of all the eggs in the clutch failing to be homozygous. Subtracting that from 1 gives you the odds of everything else (one or more homozygous).