Pulling a transmission out is pretty straightforward, even I can do it. The major issue will be that those top loaders are very heavy pieces.
With a hoist and a proper transmission jack it can be a one man job but with the car just up on jack stands and ramps and using a floor jack the weight and unwieldy nature of the trans mean a second pair of strong hands is pretty much essential.
You can get adaptors you bolt to a floor jack to make them a kind of trans jack - kind of an adjustable cradle thing - that then holds the trans reasonably steady. The problem with this is that the jack at its lowest point, cradle and trans then sits up too high to get it out from under the car if its just up on stands. In this case that might not be a such a problem. It could be used to remove the trans, drop the jack to its lowest and just roll the whole thing back under the tunnel enough to get access to get the bell housing off to access the seal.