The simplest thing to do is to 'triode wire' the pentode. This involves connecting the suppressor grid (g3) to the cathode and the screen grid (g2) to the anode. You could wire it as a proper pentode though, connecting the screen grid to HT via a resistor decoupled with a capacitor. A quick read through Paul's section on 'How Valves Work' would probably help:
http://www.vintage-radio.com/repair-...lves-work.html
HTH, Paul