Torque wrenches are easy to use mate, they're basically like using a socket set that doesn't let you 'Over tighten' the bolt. Instead you hear a 'click' when it's tightened to the right torque. Find out what this is first...
As for the plenum, I removed mine the other week. Piece of cake. Don't rush it, if in doubt lay all the bolts out in the order you've removed them in. Try getting a magnetic tray instead of putting them in the scuttle panel like I did.
If your cars got a plenum spacer in, there will be spacers underneath the strut bar, be careful when taking the bolts out for this because the spacers could slip down inside the engine bay, and if they're alloy like mine were, a magnet won't help.
Also. Remember to plug the MAF sensor back in afterwards...