talon questions

new to talon air rifle so please bear with me.

i have a standard .22, 18″ bbl airforce talon, with a standard talon air supply bottle (as far as i know) as purchased from an over the internet dealer.

1. where/what do i get tool to dissemble air tank valve?

2. what size to drill out air valve once removed?

3. how to disassemble air valve? any special tools?

i have a lathe and drill press and am capable of doing most DIY mods involved in airguns (i did my own QB78 with good results)

perhaps a sticky that gives all the details or a good website that explains mods and how to do them.

thanks