Canon Adv C5030 Poor Copies Quality, Prints look Great

[wingit]

Happy New Year to All
Can a canon tech guide me in how to clean all mirrors in The reader, The service manual on 7-19 Parts Replacement and cleaning Procedure does not explain to get to all the mirrors. I can reach the first 3 after removing the LED lamp unit. Does this mean I have to remove the top 2 mirror's to access the other mirrors ?.By the way my customers Prints look Great. My Copies look Weak on one side. This copier is in a machine shop environment, (lots of oil) floating thru the air. Copier is in the front office. I have never cleaned the scanner mirrors since new, never had too. I have cleaned the laser unit 3 times over the years, with only 420K. Any help would be appreciated. So I am believing my problem is in the reader only. All Machine Prints look great.1,5,10.
Thank-you

[wingit]

Problem resolved, I went back because customer called for light copies when copying,scanning to thumb-drive and scanning. The blacks where good only on one side I ended up removing the top mirror with the black clips, and the mirror underneath I could not reach without removing the top mirror, was dirty. I put the top mirror back on and the copies look marvelous. Not sure if this is how its done but the manual did not have this procedure to reach the bottom mirror, It Worked. Thank-you all.