rotten subloor

There is no one step by step single way to do this. The objective is always the same (support the wall so you can take the load off the element you want to replace), but the temporary structural elements are determined in the field, based on load paths and the surrounding "good" structure that you have available. It goes quick when you assess it properly and get your temporaries in place. But I've seen contractors struggle for an entire day or more fiddling with the assement part, when it really shouldn't. I did one a few weeks ago that involved the sill, joist ends, and subfloor in one quadrant of a house, and it took 2 framers about 3 hours to put proper supports in for that corner of the house, but you have to know what to do and have the right material, which requires that you have a very good understanding of the load paths in the structure you're working on.