I have an older North Star M11900G log splitter and can't figure out how to check the hydraulic fluid level or add the fluid. When I remove the nut and washer (left in the photo), all I see is this rubber plug that fits very tight (right image). How do you remove that plug? Any ideas? I'm at a complete loss on how to figure this out. Thanks for any help.
![[Hearth.com] Help adding hydraulic fluid to log splitter [Hearth.com] Help adding hydraulic fluid to log splitter](https://www.hearth.com/talk/data/attachments/226/226184-6f703eb33e3c75f0d0e9090a6f076c60.jpg?hash=2ueGv2fZIM)