never done it on x but did it twice on m.

I didn't use pressure washer. was told to avoid it. I used engine degreaser. lightly warm up the engine first. don't make it hot. just warm enough for degreaser to act faster.

then shut off engine. cover the electronic parts as much as I could. wrap with paper towl or food plastic wrap first and then wrap again with aluminum foil(stole all those from my wife's kitchen). cover things like xenon ballast, electronic connectors, alternator, ...etc. spray the degreaser and let it sit 10-15 mins. you can lightly brush some seriously greasy spots while you're waiting.

then just hose down the degreaser with water. if your water source is well water and it's usually cold, you should consider using bucket with warm water.

once done, wipe excess water and start engine to warm up engine. remember to remove those aluminum foil..