A pipe spanner is the same as a ring spanner but with a slot cut out of it to slide through the brake pipe so you can use as much of the spanners hex as possible.
While we are on the subject of brakes,,,I think some of you guys need to do a little research before advicing others about what to do. Brakes are what stop your 1400kg missile. Our Skylines have one of the best braking systems of just about any sub $60 grand car on this planet,,,look after it and it will look after you.
Vice grips SHOULD NEVER EVER be used and silicone ruining the seals is also incorrect,,,if the later was correct then you would have to change all caliper seals as well,,,go with what TT said,,,better still go buy the correct tools 1st,,,look after them and you will have them for years to come. A good trick when bleeding is to buy a big syringe and suck the fluid out of the BMC before you add your new stuff. Start bleeding from the farthest caliper from the BMC and work your way forward.
Neil.