May u advise me best option fastest by train/bus how to travel from Hongkong/Mui Wo to Guilin?

The best way is to take a ferry to Central from Mui Wo. The ordinary boat takes about 50-55 mintues, and the fast boat takes about 35-50 minutes. Upon arrival, take Tsuen Wan Line to Mong Kok from Central Station; change to Kwun Tong Line to Kowloon Tong Station; transfer to East Rail Line to Lok Ma Chau (Futian Port). The trip takes about 70 minutes in total.

After crossing the Futian Port to Shenzhen, take metro line 4 to North Railway Station (about 20 minutes). Afterwards, take a high speed train to Guilin (about 3.5 hour).

Thank you. From north rail way station shenzhen to GL. Do you know the time schedule n price for the high speed train?
Do I need to purchase ticket in advance? How?

The train schedules are 07:20, 11:48 and 14:53. The ticket fare of second class seat is CNY212 and first class seat is CNY264.5.

You are suggested to book the tickets in advance in case the tickets may be sold out because there are only three schedules every day. TravelChinaGuide provides this online booking service. You can ask help for them. The contact information is bookingtravelchinaguide.com.