How to pay CGT gold bullion ?

Hello , I've recently sold some gold bullion which I purchased 2 years ago .As the CGT threshold has significantly reduced over past 2 years I believe I owe some CG tax money to HMRC.Im unsure how to go about this , I've been on the Gov website and don't understand which forms /section I need to complete. Please can anyone advise on the process ? thanks Stev e

Hi,
You can see guidance below as it also covers other property, assets and gains and includes a calculator to help work out if there is a gain:
Tax when you sell shares
If there is a gain, you can either report it below or in your Self Assessment tax return for that year:  
Report and pay your Capital Gains Tax
Thank you.