2. Seek bank guarantee to redeem the building. If the buyer consults his bank account manager who is preparing the mortgage, he will definitely help you find a way. If it is an informal bank account manager, they will charge you. Generally, he is willing to help find a guarantee company, because you have already given him a "benefit" by giving him a business loan. Help you redeem your property, and you can go through normal transaction procedures.
3. If you are trading through a real estate agent, you can seek the help of the agent. Generally, similar to the larger intermediary companies in Beijing, Shanghai and Guangzhou, they all have bank guarantee lines, and they can redeem the mortgaged property through the bank and go through normal trading procedures.
In short, it is not recommended to use your own funds to redeem the house for the seller without any risk protection. If there are formal channels, you must choose. It is not very cost-effective to redeem the house for the seller from private financing or through intermediary high loans. You should be able to calculate this account.
I know the national market, and the guarantee rate of buying and selling will generally not exceed 1% (that is, the use fee = the amount owed multiplied by 1%). I hope you know something about this. Good luck!