Soundlab voice coil setup

just bought a damaged Soundlab P 18110A.
The magnet has come loose and is jamming the voice coil. I think it has taken a knock in transit.

I have found 4 allen keyed bolts around the spider but they do not hold the magnet tight.
How do I get in to adjust the magnet to centralise it around the coil?

Or do I remove the cone and coil and do all the adjusting from the front?

What is behind the manufacturer's label on the back of the magnet?