Help removing the square handle on a Smeg MDQ5-CSP tap

[PiersWilson]

I have a Smeg MDQ5-CSP tap that needs a new cartridge (part number 68503). The MDQ5-CSP tap is in a difficult place to remove, so I am planning on replacing the cartridge in situ. To replace the cartridge I need to remove the square handle (part number 113453). I have removed the cap which reveals the hole but I can’t clearly see inside. With an inspection camera it looks like it may be a security torx, but in not 100% sure. I have tried both hex and torx keys, but neither are working. I wonder if I need a 27 or 30 torx security key, but mine is too fat for the hole. Dose anyone know the internal make up of Smeg taps? If so, any suggestions what tool is required. The tap is quite old, but cost over £400 and still looks great, so if I can sort the issue with a relatively affordable cartridge that save me a lot of money and help the planet. The exploded diagram is attached.

Any suggestions greatly welcomed.

Many Thanks

Piers

 

[PiersWilson]

HI all,

I have now removed the grub screw from the handle (it turns out I had already undone it, but it was still in the square handle). Now I cant remove the handle, and don't want to force it. Any suggestions? thanks