S400 Classic. Leaking firing valve

[swylo]

Hi,.. I have done the balloon check, and well as many/all other leak checks.
I am now confident that the air is escaping from the barrel, therefore I am aware now that it is the firing valve that is leaking.
What I would like to ask is,....
Can I do this repair myself??
Will I need to go through the motion of drilling out the anti tamper plugs etc ??

Any advice would be helpful,...thanks.

[Roger5]

It is certainly possible to do this job yourself, but, you will have to remove the antitamper, once that's out, they are pretty simple, you will get plenty of help here, that is once you've removed the A/T