This is actually a quite easy job.
First, remove the coils.
Next, remove the valve cover bolts.
Gently ply up the valve cover. Remove the cover off the engine.
Clean all mating surfaces to a shine being careful not to scratch the surface.
Apply black silicone sealer to the cap corners. Just a small dot not too much.
Reinstall the cover, bolts, and coils using the following torque figures.
Now, here's the trick to a good repair. Once assembled, wait a few hours (4 to 6) before you start the engine. This will let the silicone cure. This is also a good tome to change the oil and filter.
Of course, use a new gasket set. Replace the ignition coils or just the coil boots (if you can locate them).
Use only BKUR 7 ET (NGK) spark plugs. Or F6 LTCR (BOSCH). Do not use any other spark plugs as premature coil failure can occur.
Feel free to let me know if you have further questions. Thanks.