If your neighbour's tree(s) is overhanging your property, we first advise you to talk to your neighbour - they may be unaware that it is causing you a problem.
Take some time to think about what problems you are having, write them down if it helps, so that you can approach your neighbour calmly. Sometimes taking a few photos to show them can help them appreciate your concerns.
If they decide not to act, then you can arrange to prune back any overhanging branches - but only as far as the boundary. Remember to return the branches to your neighbour or ask them how they would like the branches disposed of.
Before you do any work we advise you to check whether the tree is protected. If it is protected you will need to apply for consent to do the work.