hey guys

just quick one would a haynes manual tell me how to change engine bearings and that stuff thinking about doing it myself.
I have a good-ish mind about engines and stuff so thinking about just giving it a whirl

basically i have a knocking noise from the engine with the oil light flickering (rarely) im guessing its a low oil pressure issue, i will be giving it a service on tuesday to see if that helps if not i will change engine bearings and stuff and then start to upgrade parts.
has anyone done this or know how to? just need some advice cheers guys