The 3 main ways to steal 10 mllion votes are low tech (Sealing return envelopes for mail in ballots) , High tech (block chain corruption of election results) , and government sponsored voter suppression, (purging voter rolls, closing voting locations and allowing deliberate corruption).

I could explain each one in detail but you get the picture without having to mention Russia which is a 4th way. Since JFK, rigging elections has become a high growth industry inside of politics coming to a head with both Bushs and now with Trump.