It's OK Trev. We all know how you feel starting out...
Here's what I did:
1 Load all three images into CS3.
2 Select one - say the red channel.
3 Create a new layer (Layer
4 Select the green channel image, and then Select All,
5 go back to the red image and make sure the new layer (Layer 1
) is active/selected, then paste in the green channel image.
6 Right click on Layer 1
in the Layer Control, and choose Blending Options
7 In the pop up window under Advanced Blending
uncheck the red channel, and click OK.
8 Create a new layer for the green channel - Layer 2
9 Copy the blue channel image and paste into Layer 2 as you did before.
10 This time right click on Layer 2 in the layer control, choose blending options and deselect both the red and green channels.
If layer 2 is not on top of layer 1, either drag it on top or go back to layer 1 and turn off the blue blending checkbox as well.
Hope this helps.