Take the SS Aqua to go to Olivine City.
Chat with our AI personalities
go to bccghfdh
Board the Ship which says Slateport city in Hoen
It's the house on the left of the Olivine Poké-center
You get HM Strength from the sailor sitting at the big table in the building to the west (left) of the Pokemon center in Olivine City
To go back to Vermilion City in PokŽmon Global Revolution you need to go into and out of a few doors. Once you have visited a few doors, you will be able to go back.