Honestly,it would be cheaper to get someone with a kit to do it for you.The reasons why :
it will be cheaper than buying a kit
you dont want to be learning to use a kit on a piece of pipe that you cant afford to get any shorter
from MY experience,the block in vice type of flare tool is easier to get the job right first time with no previous practice
....however,if you dont want to remove the section,and you think there is enough length to make a new joint without stretching anything,then you may well have to use one of the cheapy tools.They DO work,just not as well,as easily.
However,again,do you really WANT to go half arsed on your brakes? Me,for the cost of a new section of pipe and fittings,I would rather my vehicle be safe.Sorry,old and boring.
It used to be that you could go into any small independent car spares shop and they would make you a pipe up to match on the spot.....but there arent that many of those shops left.So....stick your head round the door of your local small car REPAIR place at a break time and ask "who wants to earn a tenner?"