Let me CAUTION
any DIY that is thinking about dis-assembling a toilet for no other reason than to make it easier to move out of a cubby hole.
In the category of: If It Ain't Broke Don't Fix It!
In most cases two-part toilets have seals inside the tank and between the tank and the bowl frame. Typically these seals are made of rubber and over time the rubber will harden. Once that seal is disturbed the rubber components may not compress a second time when reassembling the parts and leaks will develop. NOW, one would have to find the proper rubber seals for replacement. That in and of itself could be a real hassle and time consuming. "Don't mess with those seals."
In the case of replacing a wax ring seal at floor level...
When the toilet unit is placed over the hole and onto the wax ring seal it should come to rest slightly above the floor being stopped by the height of the new seal. It is then necessary to apply some weight to the toilet unit to press it down to the floor thereby compressing the new wax seal and assuring a proper fit.
If one finds the toilet immediately sits on the floor with no resistance from the wax ring seal then YOU DON'T HAVE A TALL ENOUGH SEAL. In that case, one additional seal can be added on top of the first seal.
Seals come in a standard size, in addition there is an "extra tall" seal size. In addition to that, wax ring seals also come with a plastic funnel built into the wax ring. The plastic funnel type seal is what I recommend to go into/over the hole first. Then, if additional seal height is required, a second wax ring seal WITHOUT the funnel can be placed on top of the first.
Stabbing the bolts also isn't rocket science.
Most bolts have a retainer that threads down on top of the flange thereby holding the bolts firm, straight, and erect. In the absence of the retainer device, plumber's putty or even modelling clay can be used to pack around the bolt in the flange and again hold the bolt firm, straight and erect. Toilets aren't THAT heavy and re-stabbing them over the bolts isn't a real challenge.
If one is still having an issue viewing the location of the bolts and thereby stabbing them, one can slide a soda straw over each bolt thereby increasing the height and visibility of the bolt location. Once the toilet is in place, remove the soda straws and install the remaining hardware.
DO NOT use the nuts to draw-down the toilet. The nuts are only used to snug everything into place. Too much tightening could crack/break the toilet and ruin it.
The entire toilet unit should be in its final resting place BEFOR any attempt is made to tighten the nuts onto the bolts.
AGAIN, separating the tank from the bowl for no good reason could be a foolish and stupid mistake, DON'T DO IT, without a good reason.