What are the documents that myself and my wife required to apply for visit visa for Hong kong.

Dear Sir,
I am a Nepalesse Passport holder with Indefinite Leave to remain in the UK( ILR Residency Permit Visa). Also I am an Ex British Gurkha Officer retired after serving 23 yrs and living in the UK With my wife. We both myself and my wife would like to visit Hong Kong for shopping on visit visa and then fly to Nepal and fly back to UK. Therefore, please advise what are the documents that we need to produce to obtain it for Hong Kong.
Yours faithfully
Tilak Chandra Thapa
2 Gower Street
Reading Berkshire
RG1 7PE UK