From Richmond-Brighouse station:
1) Take the Canada Line train heading towards Waterfront Station.
2) Get off at Broadway-City Hall station.
3) Take the 99 B-Line bus to Commercial-Broadway station.
4) Take the Expo Line Skytrain heading towards Surrey Central station. The Millenium Line train also travels along the same path as the Expo Line (both trains depart from Waterfront Station, but after the Millenium Line train stops at Columbia, it goes east towards Sapparton, Braid, Lougheed Town Centre and continues along up until VCC-Clark ).
5) Get off at Metrotown station.
6) Follow the signs to the Metropolis at Metrotown shopping centre.
Alternatively, you can take the 430 bus from Richmond-Brighouse station and that bus will take you to Metrotown Station - however, the 430 only operates during the rush hours.
Outside the rush hours:
1) Take the Canada Line train heading towards Waterfront Station.
2) Get off at Marine Drive Station.
3) Take the route 100 bus at Marine Drive Station.
4) Get off at Marine Drive at Greenall Ave.
5) Transfer to the 116 Edmonds Stn/Metrotown Stn bus heading towards Metrotown Station - heading northbound.
6) Arrive at the Metrotown bus loop.
If these steps are complicated to you then use these steps:
1) Take the Canada Line train heading towards Waterfront Station.
2) Get off at Broadway-City Hall station.
3) Take the 99 B-Line bus to Commercial-Broadway station.
4) Take the Expo Line Skytrain heading towards Surrey Central station. The Millenium Line train also travels along the same path as the Expo Line (both trains depart from Waterfront Station, but after the Millenium Line train stops at Columbia, it goes east towards Sapparton, Braid, Lougheed Town Centre and continues along up until VCC-Clark ).
5) Get off at Metrotown station.
6) Follow the signs to the Metropolis at Metrotown shopping centre.
Otherwise, if you want to bypass Vancouver, then follow these steps:
1) Take 410 22nd street station bus at Richmond-Brighouse. Make sure the 410 goes to 22nd street station!
2) Get off at the bus loop at 22nd street station.
3) Take the Expo Line or Millenium Line train heading towards Waterfront station.
4) Get off at Metrotown station.
Although, I haven't been to Vancouver in recent years (I last visited YVR back in the summer of 2004 - as a personal note, I stayed at my uncle's place in Surrey), I hope this information helped you a bit. Cheers.