First thing you need to do is get a "Maverick" Helicopter either from the San Fierro Airport or the Police Station also at San Fierro, then fly it over to a block in Los Santos that Grove Street runs ( it will be highlighted in GREEN on your map) and recruit some gang members (max. 3) and hop back in the Maverickand the other members will get in the other doors. If done sucessfully you will be able to fly your gang members around Los Santos,San Fierro or Las Venturas.