Excellent. I ran out of time earlier but wanted to get you started the right way. At the lens mount, there are the 4 screws that hold the metal mount on. And there are 2 small screws perpendicular to the mount contacts. These hold the electrical contact plate plus the contact plate has a plastic alignment tab.
The order of removal (if possible) is to remove the rear grommet that surrounds the last element you see from the rear. On some lenses this has flocking on it. You can either take a very small flat blade screwdriver and pry where it meets the edge of the contact plate or use your finger or thumb to pop it out. If neither way works, you can remove the 6 screws mentioned and gently pull away the mount plate to get access to the plastic tabs that hold this grommet in place. Once the mount, contacts and grommet are out of the way, you can go further into the lens and also see what you're working with.
That grommet sometimes has that translucent blue glue that Canon uses which can make it difficult. There is no need to re-glue it back in during reassembly.
Ribbon cables can go in various ways. Most cables have a slide lock or simply push in to place. For slide lock, you want to evenly push both ends out toward the ribbon cable. It will stay attached but overall movement is about 2mm give or take. Then you can pull out the ribbon cable.
The push in cables, I just use my fingernails to grip the little detents built into the cables to rock them in or out rather than a push in or out. Seems to go better with rocking it side to side.
Lastly, there are many youtube videos for various Canon lenses and while they arent't your lenses, you can glean a lot of useful information of what you'll encounter and how to do it.
Let me know if you need help. Oh and I just had a idea. If you want a trial run, grab a kit lens 18-55 or some other cheap lens off of ebay and do a full tear down. You won't need to worry about whether it survives but it might be better than going into the L first.