removing the locals (to put it mildly) etc.
Virtually the entire indigenous and otherwise non-Slavic population (some 30 percent of the total population of the peninsula) to be precise, according to this graph:
https://upload.wikimedia.org/wikipedia/commons/6/6a/Ethnic_P...
The original Russian colonization of Crimea brought in many Ukrainians as well, though, so that alone did not make it lean Russian so strongly by itself. The naval facilities in Sevastopol, though, meant a lot of military personnel with their families from all over the country would come and settle in the city, and that specifically tilts the popular opinion there today strongly towards imperial Russian irredentism.