HDB ownership transfer from parents

Hi everyone, I’m currently staying with my parents and they have bought a new house which will require them to sell the current house we’re living in because of the housing law where they cant own 2 hdb flat

My parents has offered to gift my fiancee and I the old house and we’re wondering how we should transfer ownership?

What is the most cost efficient way? Anything I should know?

Tried calling HDB but they refer to me sales agent, would like to ask fellow redditors first since I have very little knowledge about housing laws in SG.

Thank you very much!