Using a front tine tiller to break up sod and prepare a garden spot is back breaking work but it sure beats digging it up with a spade and a fork. Some advance planning can make this job a lot easier as these tillers are available in various sizes at local rental shops and you should try to rent a tiller just large enough to do the job, but no larger. For really big jobs use a rear tine tiller.
Mark out the area you wish to till. Plan to begin tilling in one corner of the plot and working the soil in the long direction of the garden.
Determine the tilling depth and set the stake on the rear of the machine to that depth. This stake helps the machine maintain a uniform depth.
Start the engine by applying the choke, opening the throttle about half way and pulling firmly and quickly on the starter handle. Once started, return the choke lever to the open position. Allow the engine to warm for a minute or so at idle speed.
Open the throttle to speed the engine up. Full speed works best for tilling, but will make the machine harder to control.
Engage the tines by squeezing the engagement handle. The tiller will jump away from you at this point if you do not have a firm grip on the handlebars.
Bracing yourself, allow the machine to start tilling the soil while also allowing it to propel itself forward. Be prepared for the machine to lurch and buck as it hits rock and dense chunks of sod. When the machine stops its forward movement, try rocking it side to side while attempting to push it forward to get it moving again.
Make multiple passes over the area you are tilling. If possible make the passes from end to end and then side to side. Then reverse direction and go end to end again. The more passes you make, the smaller the remaining clumps of sod become. This makes raking easier when the tilling is done.