Adblue refill

I have a 2009 Touareg TDi. Last week I purchased the 1/2 gallon Adblue bottle at the dealer. The parts guy told me that I could refill the bottle with bulk DEF and refill the tank. However, I cannot seem to figure out how you can refill that container. The adapter portion does not appear to screw off.

Any ideas? I really dont want to invest $299 in the refilling tool.

Thanks

this should help

http://forums.tdiclub.com/showthread.php?t=295974

Short version is you cut the bottom off the 1/2 gallon bottle and use it as a funnel. All you want is the shut off valve to keep from spilling if you overfill.

I just use a regular funnel with my Touareg. The opening is large enough that I can see the fluid level when near full.