Yes, this is a big job...
The front manifold needs the right-side fuel tank out of the way, so it can slip through that area and out the wheelwell. Be careful when draining the tanks!!!
I found that the rear manifold needs to be taken out from the bottom and you need to raise and push forward the entire engine to clear the differential. Now remember, my car is a US version and thus has aluminum heat-shielding on the manifold. This makes it very thick and the reason why it made me move the engine to pull it out. If your manifold does NOT have heat-shielding, it can probably slip out from the top (or bottom) without moving anything (except, maybe the fuel distributor unit if pulling from the top).
I'll warn you that the nuts holding the manifold maybe seized and it'll be difficult to remove - keep alot of bandages handy on the workbench! If your car has the exhaust-gas-analyser pipes mounted on the front manifold, you may try, but I'll bet that they'll be next to impossible to remove. If you break them (which I did), you can substitute with stainless tubing and compression fittings, available at hydraulic-supply stores.
Which system did you get?