Transfer money from Hong Kong

My cousins are domiciled residents of the UK. They will promptly transfer all their past savings and inheritance money from Hong Kong to the UK. I would appreciate your guidance on the necessary steps and forms to fill out when transferring my past savings and inheritance to the UK. Thank you so much!

Hi Martins Family,
Please refer to guidance here:
Paying tax on the remittance basis (Self Assessment helpsheet HS264)
Thank you. 

I apologise for my oversight; they have clarified that they are residents who are not domiciled. Do they have to pay taxes in this scenario if they send all of their money to the UK before April 6, 2025? Thank you so much!