These are the things you'll need to disassemble and clean your solenoid: small phillips head screw driver (such as the ones used to repair eyeglasses), q-tips, Dow/Corning 33 Shocker lube (aka. Molykote 33), needle-nose pliers.
This preceedure outlines the complete diassembly of your marker's solenoid valve. You must find a flat, clean surface to do this or you may damage or loose one or more of the solenoid's many small parts. The pieces are very fragile and you need to use caution (they are also expensive). It will be easiest if you disassemble the rest of the gun as well, meaning remove the vertical adapter, frame, etc.
Read through this entire guide before performing the activity.
To access the solenoid you must remove the frame. To do this, unscrew the two screws holding it to the body using a 1/8" allen wrench (note that Nerves use a 5/64" wrench for the rear screw). Once the frame is off you can disconnect the wire harness connecting the two circuit boards. Simply pull the harness out, but gently and not too hard in either direction. Set the frame aside. Also disconnect your Vision eye ribbon as well (if present). The solenoid is located on the underside of the body:
The solenoid has three main sections: the coil, pilot, and spool housing. Attached to the top is the upper circuit board. Connecting the solenoid to the body is a piece referred to as the solenoid manifold.
The only part of the assembly that needs to be serviced is the spool, which is a small piston located within the silver section of the solenoid (the part that attaches to the marker). To access the spool, unscrew the two lateral screws that hold the small endcap over the end of the spool housing. When it comes off, you will find a small spring and a complicated Buna gasket between the endcap and the spool housing. The gasket may be stuck to the side of the spool housing, or it may be stuck inside its groove within the endcap. It doesn't matter; just be sure not to loose it.
You can see the end of the spool exposed within its housing. To remove the spool, use a pair of needle-nose pliers to grasp the small nipple visible on the exposed end of the spool piston. If you are unable to remove it using the pliers, don't waste time deforming the spool; instead proceed to disassemble the rest of the solenoid as detailed below. Often the spool won't come out of there so don't worry about it.
There are a number of Buna o-rings around the spool. All you have to do is clean them off and apply a very thin coat of grease, then use a q-tip to clean the inside of the spool housing as well, however take note not to leave any tiny hairs in there. Try not to overgrease the spool.
If you weren't able to remove the spool using your pliers, you will have to disassemble the rest of the valve. To do this, remove the other two lateral screws from the end of the coil. You will have to remove the solenoid spacer screws to get the board off. The board is NOT removeable, don't try to take it off!
When you get the screws out, you can separate the pilot from the spool. The pilot is also threaded for the screws so they will be stuck in there. You can remove the screws if you wish, but it isn't necessary, so I don't suggest it. Located between the pilot and spool is another dynamic gasket, and there is also a circular o-ring between the coil and pilot (if you remove the screws).
You can now push the spool out of its housing (either direction), and clean and re-grease it as per the above instructions.
Excersize extreme caution when handling the various gaskets within the solenoid; most would agree they are definitely one of the more fragile parts of the marker. It is best to keep them in their grooves, lest they be lost. It is also very important that you not further disassemble the pilot section, as doing so without proper precautions will damage it, and the solenoid will no longer function. Again, even though you can remove the screws and have access to the inside of the core and pilot, this isn't necessary so you mind as well not bother.
Reassembly of the coil/pilot half of the solenoid is straightforward; simply put it back together exactly as it came apart (in the above picture). The manual override button on the pilot faces away from the body, and is closer to the coil than the spool (in other words, the white circle end of the pilot faces the spool). Use the diagrams for reference.
Simply slip the spool back into the housing, then place the tapered endcap spring over the end with the nipple, then reinstall the endcap (with its butterfly gasket properly seated). The nipple should face the front of the gun. When reinstalling the spool endcap, you must take care to install it with the small line facing the body. If the line doesn't face the body, the marker will leak, not cycle, or the bolt will remain forward.
Before you reassembly the solenoid you can tighten the two solenoid manifold screws using your 1/16" allen wrench, if needed.
This is an exploded diagram of the Parker solenoid.
These videos show highlights from quickly disassembling, cleaning/regreasing, and reassembling the solenoid. Some smaller notes are left out of the video, so be sure you read the above page that gives detailed instructions on the proceedure.
Parker solenoid maintenance, high-res (25-MB)
Parker solenoid maintenance, low-res (11-MB)