inflate with a tube to seat one of the beads. Remove tube, add fairy to unseated bead, core out, pump for your life.
This has worked for me with maxxis HRs, Advantages & Laarsens on Crest & Arch and Hans Dampfs, Fat Alberts & Big Bettys on Flows and Sun Ringles.
I did make one of those compressors from a fizzy drink bottle & duck tape the other day which made the process a lot easier.