After designing the irrigation system on paper, go and get everything you need, remembering to buy a few more metres of pipes and some extra sprinklers.
Then use pegs and sturdy yarn to draw the path for your pipeline on the ground, and then use a spade to dig a small trench, about 20 cm wide and deep, which will contain your pipeline. If you are afraid of ruining the lawn, use a sheet of plastic, which you can place on the lawn while you dig, to hold the soil you have removed.
Once the entire trench is ready, you can move on to the laying of the pipe: place the pipe on the bottom of your channel, with extra lengths if necessary, and then place the sprinklers where you had planned to put them, making sure that the sprinkler heads are at ground level. After this operation, turn on the system, to check that all the sprinklers work and that the hose connections do not leak water. At this point you can replace the sods of turf that you had removed.