I currently have a Ibanez guitar (GRG270B) that has a HSH set up and a 5 way selector I am looking to replace the 5 way selector for a 3 way one but have no idea how to do this, below is a image of the selector I will be using (sorry about the size):

The humbucker pickups I will be using are 4 wire, Red is hot, Black is earth and green and white are joined.

The single pickup is a ibanez generic one with 2 wires which are a red and white, I am not sure which is the hot and I could do with some help with that too please?

My main question is can someone knock up a wiring diagram (I don't mind paint) for this wiring as I cannot find one on the internet not even on Seymour Duncan which is what I usually use.

Thanks in advance.
oddly enough, you'll wire it the same as the old switch. the only difference between the 3 and 5 pos. switches is the 5-way has more detents so in the 3 and 4 positions (which a 3-way doesnt have) it connects 2 throws to the pole instead of just 1.

just wire it the exact same way as the old switch.

for the pup: i think white is hot but it wont matter since only 1 pup will be selected at a time. getting the hot and ground right is just to prevent phasing issues, which only happen with 2 or more pups connected.

you can wire it either way, doesn't matter in this case.