Firstly can I ask why you wish to re-wire the enlarger, the cable looks quite servicable to me?
Anyway.......
From what I can see the plug will present no problems. It look to me like a normal 2 pin plug used almost all over the continent as far as I know. The cable may have 3 internal wires, two of these wires will go to screwed terminals inside the plug and possibly the 3rd (if there is one) will go to another terminal on the side somewhere and this is the earth return.
There appears to be a screw on the outside of the plug which will allow you to open it up to check what is inside. Make a note or take a photograph of the wires so you can refer to it if you get mixed up. You will have to replace all the wires from the lamphouse down to the plug. I'm assuming the cable passes through the enlarger column, so remove the bulb holder and check where the wires are connected to and again make a note or take a picture. Unscrew the retaining screws and pull the wire away. Now attach the new cable to the old one securely and pull the old cable through the column making sure ther is enough slack cable for full movement of the enlarger head. (I cannot see a switch in the cable so I'm assuming the blug connects somehow to a timer.)
Bare the ends of the cables and attach the to the appropiate terminals at top and bottom. Re assemble the lamp house and it now should work.
