I see, in response to this same question, that most helpful rsponders suggest "sacrifying", which I take (being in the U.S.) as vigorously raking the patches of moss. I find, however, if you will apply ferrous ammonium sulfate first, then let it sit for a few days, the moss will turn black and be more readily visible. This chemical is environmetally friendly and is contained in numerous product for this purpose. The handiest is a hose end (think ya'll call it a "hose pipe?") spray bottle. It's not expensive. After it turns black, you can rake it up and re-seed the area. You should attempt to find out why the moss encroached in the first place. Usually, it's due to the area being compacted or too shady or remaining damp consistently. Not a lot you can do about shade, but you can try to invigorate the soil and improve drainage if the problem persists... Good luck!