Create a set of gerber files, then start Kicad and use its Gerbview to export them into a .pcb project.
A lot of information is missing from gerber files, but it's a lot better then nothing.
With this method you get:
* PCB outline & locations of mounting holes.
* All copper tracks.
* Footprint locations (you can place new footprints on the ends of the existing tracks).
* Netlist (This is implicitly created when you put new footprints on the existing tracks).
You have to manually re-create the schematic (And footprint association). I once did this for a test and I made a few mistakes in the re-creation of the schematic, and those were caught because the schematic did not match up with the PCB, and DRC in Pcbnew told me where the errors were.