Ernemats:
I replaced my robin engine coils as part of a recall. Here are the major steps from what I remember, you will fill in other steps as you go. In order to get to the coils, you have to remove the engine shroud. That means pulling the engine up out of the tub enough to get clearance. That means, removing the muffler, removing the battery, disconnect the hydro cable to the tram pump, removing the front tram and rear PTO hydraulic pumps. Try to match mark the engine to the engine mount, and then unbolt the engine. Using a chain fall, lift engine just enough to remove the shroud, and then replace the coils.
When reassembling, re-align the engine to the front tram pump using your match marks and confirm the alignment with straight edges. If you search for lovejoy alignment criteria, you can find the specs. As I remember, the engine sits a little high, but within specs. It is tight getting to the engine mounting bolts. Have the PT on jack stands with all 4 tires off of the ground so that when you restart, if the hydroback cable is not properly adjusted, the machine does not take off on you. You can adjust the cable for neutral with no creep while on the jack stands. One other member who replaced the coils forgot to connect the ignition ground wire, and when the PT restarted, it took off because the hydroback cable was not properly adjusted, and he could not turn off the engine. A wall stopped the PT.
Hope this helps.