This might be stretching the definition of "regime change" and "country" *
, but China has clearly engaged in coercive methods to install just exactly the government it wants in Hong Kong and this has been getting more pronounced over time.
Dissent is not tolerated and candidates for the "elections" need to be Beijing-approved.
And... whatever happened to Free Tibet! ??? That's not a regime change, that's a straight out occupation and annexation, enforced against the will of the locals, who are deliberately being crowded out by Han settlers.
While it is tempting to look at the US's, and Russia's, activities in this domain, China has been very far from benign, as other answers have also detailed.
*
the original promise was "one country/two systems". The second part certainly has not been delivered on.