How does one apply to the new analyst and summer analyst (from undergraduate programmes)?

Blackstone was the only one that used to offer an analyst position (FT and SA) to UG's. Yet, frequent forum posts here have suggested that other firms like KKR and Bain have started it as well. Leaving aside the entire debate of a megafund vs a BB and how difficult securing these positions are how does one apply to these positions?

Blackstone seems to have an onlie application process but do the others simply post campus listings for targets? If not, should I get in touch with headhunters (would seem presumptions of me since I'm only in my last year of an undergrad from a target).

Cheers.