The idea with most of the iFixit guides is that following the instructions in reverse order is the usual way to reassemble your device. Immediately following the last step in the instructions is a big box titled CONCLUSION with the following information.
Compare your new replacement part to the original part—you may need to transfer remaining components or remove adhesive backings from the new part before installing.
To reassemble your device, follow the above steps in reverse order.
Take your new screen and substitute it for the broken one, then go backwards through the instructions. When it tells you to take out a screw, put it back in. If it says to remove a part, reinstall it, and so on.