Bad injector

[Billy7871]

I was told that my #4 injector is bad under a load (vibration feel). They want 3 to 4 hour labor @ $80 a hour. Should I pay them or do it myself. I watched Rawze video on doing a overhead and did that myself. I have attached a photo from when I did the overhead and I think the thing with the 2 wires is the injector. Is that right? Is there anything to changing out one of the injector on the cm2250?