I also talked to my maid last week about the renew contract. Basically, nothing special, just sit down and talk to her when you are free and also you must be in a good mood, just in case she has some nonsence request.
Remember to talk to her 2 months in advance, in case she refuses to renew her contract, you need to seek for a new maid, it takes about 4 - 6 weeks to proceed again.