Do so in a neutral environment NOT on your property or in a place that your maltese considers "his". Go to a park or a friend's house that is unfamiliar to both dogs. Let the dogs play and sniff each other with little intervention by you for about an hour, then take the pups home together.
Be careful, my puppy was nearly bitten when I introduced him to my boss' 3 year old male maltese. Even neutered they are still very territorial and likely won't want to interact with the pup the same way that the pup would like to interact with him (play biting, wrestling, jumping, etc.).