You can swap the crank without stripping the rest of the motor. But you need to be aware of a few things.
Frequently, there is other collateral damage from the crank breaking. Rods mangled, cylinders scored. Any of that, and you are back to a full tear down.
You will have to rig a way to keep the crank suspended as you work it in and out of the block. Even if it is just ropes to an engine lift.
You can not get all of the pistons completely to TDC because of the valves. It is important to find the sweet spot where you can get the most clearance.
Running a string around each rod helps you align the rods as you lower the crank in. You can tie each string off to hold the rod's position as you lower. Then adjust, lower, adjust, lower.
IIRC, you have to actually rotate the crank as you lower it to get it in.
Bottom line; it's a pain to do it that way.