The UK formally handed over Hong Kong to the PRC

Formally, sure. But the real transition took place through the municipal government. Beijing's control over Hong Kong stems from the number of seats on the Executive and Legislative Council occupied by Beijing loyalists.

And control of the these Councils is established through functional constituencies, which are organized by profession.

This is some Deep Statecraft shit, but the TL;DR; of it is that Hong Kong is ruled by prevailing business interests. And as Beijing business leaders own the bulk of the capital and debts, they select the city's leadership.

So how would it be possible to replicate the same scenario then?

Through the formation of economic partnerships and dependencies between Taiwanese municipal/business leadership and Beijing loyal constituents.

Taiwan doesn't operate like Hong Kong, but it remains highly vulnerable to economic pressure groups and local financial interests.

Taiwan's own corrupt kleptocracy will open the gates to Beijing bureaucrats without any need for a military invasion.