If memory serves they provide a fairly good pictorial on how to disassemble the TB. The key thing are you'll need a good set of internal snap ring pliers to remove the circlip on the throttle body shaft. Also note you have to be very careful and only apply enough pressure to expand the circlip just enough to get it to come out of its groove and slide off the shaft. It is very east to apply too much pressure and stretch the circlip.
The biggest issue many have is getting the chrome cap odd the right side throttle body to expose the circlip. I have developed a very effective method (for me) that is quick, easy and allow you to reuse the cap as it not damaged upon removal.
If you get a set of tamperproof Torx bits (HF in the US of A has then for about $7 a set) you can remove the 3 screws that hold the plastic bracket to the TB off for a super deep cleaning. Whatever you do, DO NOT adjust the throttle stop screw. It have a glob of blue paint on it. It does not matter f the paint washes off DO not move, adjust loosen or tighten this.
After I clean the the throttle bodies in soap and hot water and or the ultrasonic I rinse them with hot water then dry them off with compressed air, especially the needle bearings where the TB shaft goes through. Once I am confident the bearing are dry I put a section of tape on the inside of the opening then fill the bearing up with ATF or other light oil. After it sits a few seconds I dump the oil out then run a Q-tip around to sop up any excess oil.
s one more side note: I have taken to scribing a match line on the butterfly plate verses using a sharpie. It does not take much to wash off the sharpie mark. The scribed line holds up much better to cleaning.
Its not a hard task just make sure you are in the right frame of mind have all you tools and components at the ready in a well lighted clutter free work area stay calm cool and collected and in a few minutes you'll be done think what was all the fuss about.
Chrome cap removal:
For those who are attempting to replace and/or reinforce the throttle body pulleys on your Hex/Camhead BMW the chrome cap on the right side that covers the circlip is the biggest hurdle for most. Here is a pretty easy drama free way to remove it and not bitch it all up so you can reuse it.
Red arrows where the tip of the screwdriver will go.
Butterfly marked and top of TB marked for reference so you get everything back together the same way it came apart.
This is where I now use a scribe in lieu of a sharpie
Lower tab on the TB pinched in a vise. I used a couple pieces of cutting board as softies so the jaws of the vise did not mar the soft aluminium alloy of the TB. A couple scraps of wood would also work.
Next with a long-ish flat blade screwdriver place the tip against the cap and the shaft against the TB body (you want to keep the screwdriver parallel to the boss as possible) and give it a few taps with a hammer. Then move to the other side and repeat. You do not what to have the screwdriver at an extreme angle to the boss or it will dig into the metal of the TB.
Move to the other side and again a few taps.
Keep moving one side to another until the cap is worked off the boss.
Remember you are not driving 16 penny nails into an oak board. Fairly light strikes with the hammer against the screwdriver handle are what you use. Start out light and only if the cap is not moving amp up the strike force a little bit and try again.
Also remember to move back and forth. A couple of strikes on one side then more to the other. This will "walk" the cap off off the boss.
I've read the post where people have spent hours trying to get the cap off and eventually ruin it because they got frustrated and got out the cutting tools. This process above once the TB s chocked into the vise takes only a few seconds and leaves the parts usable
