1) That's what a lot of educated people do. Leave for better country.
2) Impossible. Anti-government people near to nonexistent inside country. Killed, jailed, tortured - dead.
3) Very difficult and long term project. There are several influential people which are managing the president of Turkmenistan. Wiktor Hramow, Aleksandr Žadan, Wladimir Umnow - all of them are jewish "dark" people. (Source: https://www.azathabar.com/a/24338115.html) They already have a system in place for electing or killing the president. I don't know too much details but they are the one designing political agenda of the country.
4) It is not possible without external support. Turkmen people are very mildly mannered.
Personally I do not support but 4 seems like only option.