There are many guides and video's on how to field strip the more popular Typhoon F12 (Aluminum frame), but no guides on the F12's little brother, the polymer frame XII.
First remove any chokes or barrel shrouds from the barrel.
Remove this nut. It may be tough to get off, if you need pliers, protect the nut with electrical/vinyl tape.
The plastic hand guard will come off easily, just slide it forward.
Next remove the red nut. Follow the same procedure as the first nut.
The barrel should come out of the receiver, it may be difficult to remove if the gun is very dirty. Make sure the bolt is forward, and let the bolt fall forward a couple of times to help free it.
Make sure all the parts are there for the gas system. The red collet stays on the barrel, and there is other piece behind it. Take care cleaning this as it has a rubber o-ring on it.
Next, remove the charging handle. This can be tricky, 3 hands help. You need to move the bolt while holding the charging handle so the charging handle is in the middle of the slot, and then pull. It's held by a detent and spring so it may be tough to pull, just don't force anything.
The picture shows the bolt out of the gun already, but it's the only way I could get a good photo of the slot.
Once the charging handle is out, the action bars and bolt will come off the front of the gun.
Here is a better pic of the bolt:
This is where I usually stop when cleaning the gun. I can get to most places that need cleaning the most. Use a good solvent like Hoppes #9, or any CLP will work. Scrub the gas system parts, taking care of the rubber o-ring.
If you want to go further and remove the upper and lower receiver, remove the stock.
Press the adjustment lever, the press harder and it should go all the way back, and slide off the back. The photo shows the normal motion, and the second photo is where you need to press it to remove it off the back.
Next, get a very long Allen key, or ratchet extension. It is a 6mm Allen bolt.
This worked for me:
Remove the stock tube after taking the Allen bolt out:
The upper receiver need to move forward. It's pressed it, but no too tight. I used brass rod to tap lightly on the back of the receiver (the aluminum part):
And we are done!
Reassembly is the same steps backwards.
If you want to remove the trigger group you can use any resource for the F12, or even an AR-15. There are springs in there, so be careful.
If you have any comments or questions you can email me at firstname.lastname@example.org