The right to unwind, as you are aware, means that you can terminate the tenancy agreement within 90 days if your landlord made false statements, omissions or carried out a misleading action - the right is automatic if you request it within 30 days and you can get your full rent for that month refunded. You will need to make a court claim if the landlord doesn't agree - you will need a declaration from the court that the contract is unwound - and you can seek compensation or a refund of the rent too.
You issue the claim to the local county court on form N1. The court will assess the claim and any defence the landlord puts forward and will make a decision. You should not move out without having made the court claim - this is because if the court decides that the contract cannot be unwound, you will be liable for the rent for the contract term.
Of course, if the landlord agrees you can move out and unwind, without the court process, you can of course move out and the landlord should issue you with a refund.
The law is the Consumer Protection from Unfair Trading Regulations 2008.
You can find form N1 here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/958344/n1-eng.pdf
And notes on how to complete the form here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/952020/n1a-eng.pdf