1) Take MTR to Central Station and then take Peak Tram or Bus 1 to the Peak
2) Take Bus 1 down the hill to Central and then take Bus 6 to Stanley Market.
3) Take Bus 40.
4) Take Bus 25A or 25C
5) Take Star Ferry to Tsim Sha Tsui and then take Bus 2 to YMCA.
If you won't stay too long at Times Square and Golden Bauhinia Square, I think it's possible to cover these in one day, since it could cost you almost a whole day for Victoria Peak and Stanley Market.