heater matrix

[datdrift]

my heater matrix has started to leak.....its not too bad, and doesent really leak during normal driving, but after a couple of laps drifting a oval, ect i loose about a pint - litre of water, and it gets annoying having to cool it down and fill it up with water all the time.
i would just loop the pipes up together and bypass it, but i need it this time of year in a stripped out car, and it helps cool the engine when drifting, so has anyone changed their matrix, and if so how hard is it to do......?