you walk into the front door... but if you mean the maids after you get the national pokedex run down the hall on the left until the maid stops you. talk to her, and you will battle five maidds in a row. you have to beat them all in one turn. I'm not sure what happens after that though, but i assume you'll at least be able to enter the door that the maid in the left hall was blocking. i don't know about the maid all the way on the right though...
you go south and find a gate
when you beat the maids and get to correct amount of rounds , the lady of the house will come to battle you with blisim (correct me)
You Can Find the mansion on route 212. When you just enter Heartrome on the south but some people are blocking so you need to go the other way onto pastoria city to go there once you beat the pastoria city gym you can go the heartrome way
go south of hearthome
go to the Pokemon mansion and then trade for manaphy
you have to go down from hearthome city
you go to the trophy garden behind the Pokemon mansion.
go to the Pokemon mansion and go left and there is a door. go in the door and talk to the guy in the purple suit.hes the guy who owns the mansion.
Go To Hearthome City Go South (Down) You Should See A Stone Fence Surrounding The Mansion.
Go to the Pokemon mansion and he will be in the trophy garden.
The Pokemon Mansion is located on Route 212 just South of Hearthome City.
Go to the Pokemon mansion and go to the owners room and then look at the book on the table.
on platinum, you see Manaphy in Mr.backlots Pokemon mansion
u go in the trophy garden in Pokemon mansion after u get national pokedex.
its 1 of the daily Pokemon in the Pokemon mansion