2 x car ramps
2 x axle stands
car jack
gasket for catalyst to bottom of downpipe,
13mm and 15 mm spanner,
and of course, the new corsa exhuast system,

first, put the car on to the car ramps, if its lowered alot then you will have to make ramps as the car ramps will be too steap,

once the front is up on the car ramps, the jack the back up and put the axle stands under the rear axle,

coat all the joints with wd40 and leave to soak for a while,

undo the two clamps,

undo the two bolts that hold the catalyst to the downpipe, take the cayalyst off the middle section,

then take the middle section off the rubber hangers and pull apart from the back box,

take the back box off the two rubber hangers,

putting the new system on is the same as above but in reverse, dont forget to put the new gasket on,

the above could be used for different cars