What is the ruling on amending printed educational curricula by adding and deleting while preserving the core material, then reprinting and registering them under the name of another institution? And is this considered intellectual property theft?

If the authors retain the copyrights of their books, and modifying them is easy and not of great benefit to the reader, then it is not permissible to print them without their permission. This is because their right to these works is legally protected, and infringing upon it is a theft of others' effort. However, if they do not retain the right to print them, then it is permissible to print them, while attributing any quoted material to its authors.