wont cost you an arm and a leg at all mate

most expensive bit is filling the new box up with gearbox oil again.

hardest bit is getting the car in the air, so its suposted on axel stands AND supporting the engine under the sump. (easier if you have an engine lift to support the engine)

remove the wheels - undo steering rack bolt - remove the hub from the ball joint - put a bowl under the gearbox - then try and pull the driveshaft from the gearbox - if its not playing, undo the driveshaft hub nut and remove the whole shaft - repeat on other side - remove the bell housing bolts, but leave a cople in at the top - undo the gearbox mounts - remove the gearbox cradle - and then you should be able to remove the box