Mr.James Brown, your cousin is your sponser, he also need to provide the following documents:

For application in which the sponsor is an Individual:
a Forms/ Documents Required: Application for Entry for Visit/Transit (Sponsor) in Hong Kong (ID 1003B)

Photocopy of the sponsor's Hong Kong identity card

Photocopy of the sponsor's travel document containing personal particulars, date of issue, date of expiry, and the latest arrival stamp/extension of stay label in the HKSAR (for non-permanent resident of the HKSAR only)

you and your brother should prepare the following documents:
Application for Entry for Visit/Transit in Hong Kong (ID 1003A)

The applicant's recent photograph (affixed on page 1 of the application form ID 1003A)

Photocopy of the applicant's travel document containing personal particulars, date of issue, date of expiry and/or details of any re-entry visa held (if applicable)

Photocopy of proof of the applicant's financial standing, e.g. bank statements, savings accounts passbooks, tax receipts, etc. and proof of employment (if any), e.g. company leave letter, salary slips, etc.

Photocopy of proof of transportation arrangement, e.g. flight itinerary

Photocopy of proof of relationship with the local sponsor

your cousin can apply for Hk visit visa for you at the Immigration Department of HKSAR Government.