19920 Chevy G20 Brake hard-line replacement
 

On my G20 I had the passenger front brake line burst under the motor. I would like to replace this line but I am finding it hard to disconnect it at the combination valve. the valves position is too far down to easily reach from the top and I cant seam to get my hand in a good position from the bottom that I have enough strength to loosen the line. it seams my hand can only find weird twisted angles to get at this thing.

Would it be best of i unbolt the combination valve so i can move it a bit to maybe get a better angle or is there just a better way to do this. (note it is cold so i will probably be wearing gloves and or have hands with no feeling which makes this even harder)

Also do you know what size of flare nut wrench i will need for these lines? half the vehicles ive worked on are metric, half are standard and half have both, not sure what this one is by default.