how do you trim a dead tree branch?

Answer 1

You just cut it back to where it has grown from the tree.

Answer 2

If it's a small branch, just cut it off fairly close to the trunk or branch where it grew.

If it's larger, cut it off in sections if possible. When you're close to the trunk, make a cut on the bottom side of the branch first, then cut it through from the top. The bottom cut keeps the falling branch from tearing a big strip of bark away from the tree when it falls.

Always, always, be safe - If you don't feel comfortable doing this yourself, call someone to come do it for you. It'll cost you some money, but it will cost you a lot more if the branch falls on your car, or house, or you.