[Closed] amateur locksmiths of stw, help required

At great expense I have bought a lock barrel for the tailgate of my Navara as they don't come fitted as standard here in Australia.

I've just been to a locksmith to see about having it changed to suit my existing key, they can do it next week and it will cost me about 25 quid.

I'm tempted to take it apart and give it a go myself. I can see it going one of three ways:

1 - all the bits come out easily and do not fly across the room, it takes me a couple of hours out work out what goes where, and it goes back together and works.

2 - the bits fly across the room when I take it apart, I have no idea how to put them back in again. I have an embarrassing trip back to the locksmith on Monday with a bag of bits, and probably end up spending more than the 25 quid.

3 - like 2 but the lock barrel is rendered useless and I need to buy another one. (About 110 quid)

Any pointers / opinions? Pictures below.

[IMG] [/IMG]

[IMG] [/IMG]

[IMG] [/IMG]