VFD error

[routercnc]

Ordered VFD from qiandingzhensatisfaction yesterday. Should be here Monday . . .

On a related note. I'm trying to remove the end cap from the top of the spindle so I can hard wire it and a get a good earth. The strain relief gland has arrived and it looks like it will be perfect.
So far I've removed the 4 cap heads but it is stuck fast. I've tried holding the main body in a vice (soft jaws) and using the largest pipe wrench I've got tried to turn and pull the end off but no luck.

All the photos and info I've gathered over the years on end cap removal only shows removal of the 4 cap heads so it must be a slightly press fit and/or a bit of corrosion. Before I start getting more aggressive with it I thought I'd check if I had overlooked something or if others had found the same?

Thanks