Code P0304, cylinder four misfire, which cylinder is number four?

Open the hood and look for the accessory drive belt. That marks the front of the engine. You start counting from that end. So, 4 on that engine is on the transmission end. That is pretty much the same on all inline engines. My suggestion would be to swap the coils in 3 and 4 and swap the plug from cylinder 4 into cylinder 2. Now if the misfire moves to 3 you can say it's the coil, if it moves to 2 it's the plug. The torque values are shown in the second image, but the numbers are hard to read, the plugs are 14 ft lb, the coil bolts are 80 inch pounds. The engine cover is the same as the coil bolt. I generally put the plugs in tight and the coil bolts and cover simply snug. No need to strip them. Now if you don't know when the plugs were changed last you might want to replace all 4 with new as they call for them to be changed at 120,000 and then swap the coils.
The coil part number is 90919-A2006 and the spark plugs are iridium tipped Denso 4702.

The permanent code won't clear until the ECU runs the tests a few times and decides that it is actually repaired. That is designed so that someone with a code reader can't clear the codes and you buy the car with the light turned off and "no known problems" as was common practice. The average person won't have a clue because the code reader they bought won't show anything until it sets a code again. So many makes added the permanent status codes that only clear after a few run cycles. Now you can see that there was a problem and ask how or if it was repaired.

We will be here when you get it back together.

Sounds like you slayed the beast. You know you have it repaired when the permanent code clears as it prioritizes the tests for the set code. Good job.