FZS1000 Gen 1 Fork disassembly ?

[ArchDruid]

Hi Folks,
I’m trying to strip the forks to change the leaking seals on my FZS 1000 Gen1, but having difficulty loosening the damper cartridge bolt at the bottom of the shock – As expected, its turning the entire damper unit inside, without loosening ….
With my previous bikes I’ve always made my own tool to poke down the fork tube to hold whatever it was that was turning.
Intending to do the same here, but can anyone help me out with the (approximate ?) dimensions of the top part of the Damper Cartridge ?
Found a Yamaha Service Tool (# 90890-01447) on the web – from the pic it looks pretty easy to make up, (or at least something that will work), but it would be helpful if someone could give me an idea on the sizing – save me a bit of trial & error.
Anything else I need to look out for ?
Cheers/

[unfazed]

I duct taped a 26mm socket to the end of a vacuum cleaner long metal pipe, held the fork leg at the caliper holes in a soft jaw vice and was able to unscrew the bolt holding the vacuum pipe by hand and turning the bolt with a special allen key for a ratchet.

[robbo]

Exactly what unfazed said , and don't use thread lock on the cartridge bolt when you reassemble.

[PieEater]

The way the workshops do it is to use an airgun on the bolt which gets the bolt spinning faster than the cartridge and frees it up. I've replicated this with a power drill and an Allen key that I hacksawed the right angle off leaving a straight bit that would fit into the drill. It can take a few short sharp bursts but normally works.

[topgun44]

I did it with out taking them part I use good ole hammer and screwdriver doing it that way for last 30 years works for me