I have a 2000 Ford Ranger Auto V6 4 Litre.

I had been experiencing the bouncing oil pressure gauge that I have read about, and then as I was driving home from work it suddenly dropped and didn't come back up. Just before I got home it began making a ticking noise and I kept driving ( I was only 3 minutes from home, but unsure of when the noise had actually started..) I didn't drive it for 3 days after because of the noise, and my dad had turned it on to listen to it but the noise had gotten a lot worse. We had it towed to his shop and he has checked the pressure and everything and now he wants to replace the oil pump but we aren't sure how? He wants to just pull the engine out, but if anyone has any tips or ideas of what we should do that would be greatly appreciated!