Rudder post deck cover

[Ailatan]

My rudder post deck cover is impossible to remove.
Does anyone have a good idea to unscrew the cap or know where can I find the replacement?

[Ailatan]

Problem solved

[Krumelur]

An oil filter remover would have been my next suggestion but glad you solved it!

[Ailatan]

Thanks for the advice I tried with this tool, which is similar, without success