Tuning Brocock bottles

Good question. Daystate is famous for REALLY locking stuff down tight. Maybe somebody knows.

I know you have to degas the gun(CAREFULLY loosening manometer/pressure gauge OR getting the special tool to loosen the fill port), but after that, I'm not sure if you just unscrew the REALLY tight steel bottle, or if you have to disassemble and remove the "block" between the bottle and the receiver.

I did a search and found this old thread:

https://www.airgunnation.com/topic/brocock-bantam-tuning/

A couple different things going on here(installing reg, adjusting sling shot hammer, etc...), but down further in the thread there is discussion about having to remove other things before removing the "tank"? A couple different voices talking about a couple different things. Hard to follow exactly what was meant. Explain it to me if you decifer it.