I concur with Paul L. in säga upp meaning to give notice.

Low confidence level as I have no idea what the target or object of either verb is. Revoke may be alright for the second one in some circumstances,

In the weblink it means give notice to terminate with immediate effect. The DEU 'equivalent' once caused a professional negligence claim at my erstwhile London translation office when den Mietvertrag zum .... am ... kündigen > SE: säga upp avtalet på till upphörande dagen cf. the second ProZ weblink

- meant giving notice to quit in a lease on ... a date... 'expiring' so effective on a future date. The two dates got mixed up and it was too late to get the tenants out when the notice was supposed to kick in, lumbering the landlords with the tenants in Franfurt am Main another year.

BTW, a legally unqualified office director once doubted someone else's translation of 'determining' a lease by notice to terminate, though IMO it had been a sound-to-excellent legal translation.

Contracts can be cancelled - contrary to the word of Solicitors and Barristers at a contract workshop in London claiming it was 'impossible' cf. the UK Consumer Credit Act 1974.

Also in ENG law there is a grave doubt - as regards häva - whether rescission can be unilateral as opposed to ordered by the court or mutually agreed by both or all parties to a contract.