Recolour .ai artwork

I have 3 pieces of artwork that are basically one illustration, I have just split it in to 3 pieces to allow me to layer the out files in a web design. I basically just need to artwork recolouring. I have the illustrator files, I have the target artwork colours in a different .ai file, so you can extract the colours to use for the recolouring.

Basically the client does not like the overall yellow in the design and want it to match other graphics being used.

I have uploaded 2 images (for examples), 1 of the yellow (to be edited) and 1 of the target colours.