I have not yet used the ones that I bought (two tests, €7-ish). We also this week got a letter in the post, with a code to order two (free) self-tests, from the government. I opened one test to see how its done. It uses a q-tip which you stick in your nose (not like the ones where they went 6 inches in) and you twirl it around on the inside of your nostril. Then you put the tip in a little plastic thingy which contains a fluid (you have done something with this thingy beforehand, to prepare). Then you get a result (much like a pregnancy test result; with blue lines at a certain position, indicating positive or negative outcome).