You also need a small clamp block that allows the hose to be held firmly (but without damage) eg in a bench vice whilst the barb connector is inserted, to remake the hose connections.
Fair point but could easily machine this out of a block of wood.
very optimistic IMHO. Folk have occasionally reported ad-hoc solutions but tbh the correct tool is not expensive and is designed for the job. IIRC it has ridges on the inside so that it grips the hose without damage. The insertion force for the barb is surprisingly high. BTW a single scratch on the barb (easily made whilst the old hose is being removed from the barb) can render it useless. In addition some of the metal fittings thread into plastic parts (easy to bugger them up) and Magura also make some of the flimsiest bleed fittings known to mankind.
If you struggled to fit the brakes on the bike at all you are almost certain to come unstuck doing anything more complicated, regardless of how many noddy-esque videos you look at.
Having said that, bleeding hydraulic brakes is not rocket science and the exact procedure that works best varies with the installation as well as with the brake type.
If you have not done this sort of work before, and the only reason you are breaking the hydraulic system, is that you wish to fit the hose within the frame, my advice is that you perhaps shouldn't bother to do this.
The brake won't need bleeding if you leave it alone and if work is needed on the system in the future it is made a lot easier if you have a system that can be removed en masse from the bike.
Magura rim brakes have been around for about 30 years and most half-decent LBSs have encountered them. You could ask them about it instead of making assumptions about what they do and don't know.
cheers
