A first for me

[ZeroNeo_CPT]

So I received an illustrator file which has an image embedded but also has a few colours that are spot but going forward won't be needing these colours to be spot. The spots are CMYK that have been made spot so I proceed to make them process and all is good except for one colour. When I make the colour process the colour changes dramatically but the numbers don't change. So after checking the file out further I see that the embedded image has been colourized by this spot swatch, so when I convert the spot to CMYK it changes how the image looks. Is it possible to keep the colour from changing as I need the colour to be process CMYK. Preferably I would also like to keep it as an Illustrator file. 

[rcraighead]

The spot color may be out of the "CMYK" color gamat. If the colorized image needs to remain the same you may be out of luck. You could try to redefine the CMYK color but it is likely not going to match the original Spot color.

[Christopher P]

Following along on this one.. Tricky problem. I can't think of how you can convert a spot to CMYK without changing the appearance. As you said, the differnce can be drastic depending on the color.

Is unembedding and color correcting the image in Photoshop an option for you? You could save out an AI file with the image as is with spot color, and place a retouched CMYK image side by side and see if you can make whatever adjustments you need in Photoshop. Time consuming and laborious, but I can't think of any other solution.
I'm hoping there are folks smarter than I that know something simpler.

[ZeroNeo_CPT]

Thanks for the suggestions everyone. In the end I saved it out as PSD and use the PSD as there was very little colour shift visually. Not my first preference but working with what I had and the time constraints it was the fastest solution, lets's hope down the line they don't want the image 20x bigger down the line