Patching/Transpiling an IEnumerator + What are OpCodes?

[JArmstrongArt]

Got a problem I've been stuck with for the last few hours, I started a topic about this 2 days ago and got a very good answer but it was still a bit too much for me to understand without some guidance, so sorry if I'm being a nuisance.
I need to modify some lines from the following IEnumerator

// ItemRadar
// Token: 0x06002ACE RID: 10958 RVA: 0x000F3BCC File Offset: 0x000F1DCC
private IEnumerator RadarControl()
{
	int currentObjectIndex = 0;
	int objectsProcessed = 0;
	float distanceSq = 0f;
	RareCollectible closestObject = null;
	float closestObjectDistanceSq = 0f;
	for (;;)
	{
		if (!Singleton<PauseController>.instance.IsPaused)
		{
			currentObjectIndex = 0;
			objectsProcessed = 0;
			closestObjectDistanceSq = -1f;
			while (currentObjectIndex < this.m_trackedCollectibles.Count)
			{
				RareCollectible currentObjectInfo = this.m_trackedCollectibles[currentObjectIndex];
				distanceSq = (this.m_trackedCollectibles[currentObjectIndex].transform.position - base.transform.position).sqrMagnitude;
				if (distanceSq <= this.m_radiusSqr && (closestObjectDistanceSq < 0f || closestObjectDistanceSq > distanceSq))
				{
					closestObject = currentObjectInfo;
					closestObjectDistanceSq = distanceSq;
				}
				currentObjectIndex++;
				objectsProcessed++;
				if (objectsProcessed == this.m_numberOfObjectsPerFrame)
				{
					objectsProcessed = 0;
					yield return null;
				}
			}
			if (closestObjectDistanceSq > 0f)
			{
				this.m_fakeCollectable.transform.position = closestObject.transform.position;
				AudioEngine.PostEvent(this.m_audioEvent, this.m_fakeCollectable);
				MonoBehaviourSingleton<RumbleManager>.instance.RumblePreset(0, ERumbleTypes.HunterTonic);
			}
		}
		yield return Yielders.Seconds(this.m_radarUpdateTime);
	}
	yield break;
}

The closest I've got was the following, which I was wanting to print 'hi' every time the enumerator is called which is every 5 seconds or so in-game, but it ended up printing 'hi' 5 or 6 times all at once then never again

    [HarmonyPatch(typeof(ItemRadar), "RadarControl")]
    public class RadarControlPatch
    {

        [HarmonyTranspiler]

        public static IEnumerable<CodeInstruction> Patch(IEnumerable<CodeInstruction> instructions)
        {

            
            foreach (CodeInstruction instruction in instructions)
            {
                yield return instruction;
                yield return CodeInstruction.Call("RadarControlPatch:Help");


            }


        }

        static void Help()
        {
            ImprovedHunterTonic.MyLogger.Log(BepInEx.Logging.LogLevel.Info,"hi!");
        }
    }

I've tried looking around at other examples of using HarmonyX to modify IEnumerators as well as the docs but it keeps going over my head especially since I don't fully understand CodeInstructions or OpCodes.

Anyone know where I'd begin modifying individual lines from the IEnumerator? The game hasn't been updated in a long time so I'd also settle for being able to replace the IEnumerator with my own altered copy.

UPDATE: I guess I got carried away a bit and didn't realize the obvious that the coroutine itself is only called once and the looping every 5 seconds happens within the ienumerator itself, so of course it printed 'hi' 5 times then never again!