I don't know why you'd need a tutorial, as it's very easy.
Unplug the power connector, the scsi and floppy cables, the fan and speaker wires. Once done, find on each side of the logic board a small piece of plastic or a tab that holds the logic board towards the rear of the machine. There is an angled indent on each side of the logic board that mates with each of those tabs. One will be snug against the power supply, so it might be a good idea to take it out first (it too is just held in by plastic tabs and pulls right out/up once released.)
Push the tabs holding the logic board in place out (gently!), so that you can wiggle the logic board forward. It only needs to come forward 1/4 or 1/2 inch or so. Once moved forward, it will then be free and the swap just involves doing the reverse with the new one and various components. Everything is an exact match, so nothing more is needed than to swap the board.
The only really tricky bit will be avoiding breaking those two little plastic tabs that hold the logic board in place.