Anschutz 8002 green seal replacement

[fa38]

I have an Anschutz 8002 that needs a seal replacement for the green seal located in the recess into which I screw in the air tank.

I think I need to remove the stock to get at the seal. Yes, No

Is there a correct way to remove the old seal? Maybe I should ask what I should not do when removing the old seal.

How often do these rifles need to be serviced? I.E. checked for wear in the parts, seals replaced, regulator serviced.

Thanks

M Stenback