All the technical solutions will either remain known or are easily re-discovered. There are two big problems with rebooting society:
First, you need LOTS of people. Most of the stuff we have today relies on a certain minimum population density. That is especially true of transportation systems and without them, it would not be possible to move the raw materials around. So medical knowledge and knowing how to keep young children from dying will be paramount.
The second problem will be producing an effective counter-argument to all the superstitions, ignorance and religions that are bound to appear if "civilisation" dies off. That is what held back our scientific and technological development: From Aristotle to the Industrial Revolution there was 2,000 years of very little progress and what there was, was usually achieved DESPITE religion, not with its encouragement.
The technology will come of its own accord, but speeding it up will need manual for social survival, not designs for steam engines