The lock is a 6 pin, 54mm wide laminated steel with hardened boron alloy shackle. It has an outer cover for weather proofing and a removable cylinder. LJ stands for the long shackle version.

Here you can see the cylinder retainer and the retainer nut.

To disassemble, open the lock(use a key or pick it), pull the shackle as it has no spring, and you'll find the retainer screw. Use an hex wrench to take it out.

The cylinder without the retainer.

Picture of the shell without the cylinder, you can see the laminated core.

The cylinder has an E-clip, which has to be removed for disassembly. Insert the key, remove the clip, and carefully pull it out(careful not to loose any pins/springs).
The fully disassembled Padlock:

Notice the 5 spool drivers on the first position. 6th is a serrated driver.
Drivers closeup:
