There is a raccoon nest in the roof over my front porch. I need to call someone in to trap them. Should the tree branches used to gain access to the roof be removed before the raccoons are trapped or after?

Wait until the nuisance wildlife control operator has trapped the animals. Then cut the tree branches and make sure the opening to the roof is properly repaired. Try to make the repairs the same day if you can. The raccoons will likely be euthanized, but if the opening is still there it is possible that another raccoon may find it and use the space.