Simpo PDF Merge and Split is an excellent PDF tool. With its merge method, you can merge the whole part of your PDFs into a single PDF document.
If you just want to merge some specific part of them together, Simpo PDF Merge and Split can also make it possible. By using its split method, you can select any part which you want to split.
It can be the whole PDF or you can specify the proper part to split. Simpo PDF Merge and Split supports you to split your PDF document into separate parts by page number.
Extract method can allow you extract any part from your PDF document. It can be a single page or a specific part. If you want to remove some part of PDF document, just specify the range, you can easily do it.