I'd agree about leaving it in the box if you're not practised.

If the trees are large, get a contractor. He will have the extra
benefit to you of disposing of the all the debris; when down, a tree is
2 or 3 times the size it seemed when it was 'up'!

If the trees are not so large (and I myself would take down one with a
trunk up to a foot thick), nobody else has yet said:

- saw off all the boughs progressively from the top down.
- saw off pieces of the trunk until it's about 8' (that's feet) tall
- dig round the roots, attach a rope to the top of the 8' "stump",
recruit the neighbours (or use the car) and pull the stump over.

There is no work in the garden harder than digging up a tree stump, so
use the leverage of the tree itself to do you that one last service.

have fun
john