Here is a pictorial explanation of how i in this case cut a Cheena, but works the same for a Jackfruit, so that none of the seeds are damaged and you don't get the sticky latex from the center core on your knife or hands:
Here i have the cheena fruit on grass, but it's better to place it on a piece of clean cardboard because you're going to have to roll the fruit after the first section is removed and you want to keep it clean. You might want to use some butcher paper over the cardboard to keep it even more sanitary:
Cut a wedge with your long knife, i like to use a butcher's knife, a lengthwise section about 1/6 of the fruit. Cut it about 1-2 inches deep, depending on size of fruit:
Pull from top to remove first section:
Here is what the fruit will look like with first section removed:
Once you've removed peel from first section remove all the arils and place into bag or container. Or if you prefer you can do the fruit separation at the very end all at once:
I like to separate the seeds from the arils, but you can leave them in, depending on what you will use the fruit for. Once the fruit from that section is removed then roll the fruit to one side and repeat the process until whole fruit is done. Or skin the whole fruit all at once and separate all the arils at once. If you want you can even just remove one section for instant eating, and place the rest of the fruit in fridge and continue later when you want to eat some more. The arils keep a whole lot better refrigerated inside of the fruit than outside of the fruit. If you take all the arils out at once but can't eat them all you can freeze the remainder in freezer zip lock bags. This whole fruit filled one one gallon size zip lock bag, minus a bunch i had to eat during the process.
Enjoy!