1. Let's communicate with Jingdong Finance first to find out how to calculate and charge interest on installment payment. You can learn more about it through Jingdong Finance's customer service phone or online customer service consultation.

2. According to the interest calculation method, calculate the specific amount of interest to be paid. You can ask JD Finance to provide an interest calculation formula or a specific installment interest amount in order to understand the actual situation.

3. If you feel that the interest rate is too high, you can try to renegotiate with Jingdong Finance and reduce some interest. You can make a request to Jingdong Finance in writing or by phone, state your economic situation and difficulties, and put forward a reasonable repayment plan, hoping to get the support of interest reduction and exemption.

4. If negotiation fails, you can also consider lending to other financial institutions to replace the current loan with a lower interest rate and reduce the interest burden.

In short, if you have agreed to pay interest by installments, I suggest you actively communicate with JD Finance to understand the calculation and payment method of interest, and consider the possibility of renegotiating or lending other debts according to the actual situation to reduce the burden.