How can I improve my relationship with my partner's family and friends?

Invite them to come over try to spend more one on one them with them. Call them to ask them how their day was. Or ask if you can come over

Stay in touch with them: Call or text them frequently about their day . But face to face conversations have no substitute so try to spend Quality Time with them . Ask them out for dinner , concerts or shopping with your partner. Remember their birthday or important dates , this will make them feel that you really care about them . Show much how important they are for you just like your partner .Listen to them . Let them share your problems. Friendships need to be maintained or they will fade away , so make it a gradual process so that they may also get a fair chance to know you. In the end , just BE YOURSELF , feel what your partner feels for his /her family and friends. Your love is what all matters :)

Just behave with them the way you behave with your family and friends......it's that simple. Give them equal respect and love.