Besides the bus suggestion, you can also take the MTR to Central, then take the escalator uphill to Caine Road, then turn to the right side until you come to a convenient store, then cross the street at the traffice light. It is there.
After the visit of 孫中山紀念館, then, you turn right to the escalator (no need to cross the road), then go further up , you can visit a Muslim Temples next to the escalator if you like.