When you attempt to change the diaper of a squirmy older baby, there are three things you need to keep in mind.
1) Be calm. Getting frustrated and worked up doesn't make it easier.
2) Have plenty of toys handy. Make sure these are toys that the baby doesn't see or play with very much. You don't need to have traditional toys, either. Many things can be toys. Lately, our son has found interest in a clean, empty makeup compact, a tennis ball, a set of keys, a bath toy, one of his sister's plastic animals, and a tube of diaper cream.
3) Use prefolds with caution. Sometimes, getting a prefold on a squirmy baby seems impossible, especially if you are trying to use a Snappi clip or, god forbid, diaper pins. In these circumstances, a good fitted or pocket diaper works wonders. I can sometimes get these on him while he is standing.
4) Sing songs that engage the baby. Right now, our son likes "If You are Happy and You Know it", " "Wheels on the Bus", and "De Colores".
5) Maintain your sense of humor. Even though it can be frustrating, it is also pretty cute when a naked baby tries to escape during the diaper change, especially if he is laughing.