When CORE Generator is opened, it will search the project directory for existing IP Cores. The Existing IP Cores list is populated based on the content of the project directory.
To remove a core from a CORE Generator project, a user can simply remove the IP core files from the project directory. Note that it is only required to remove the core XCO file in order to hide it from CORE Generator. However, typically, a user would also want to remove all associated files as well.
Example: There is an IP core named "my_IP." To remove the core from the project, delete (or move) all files and the directory associated my_IP.
For a file list of associated files, you can refer to my_IP_flist.txt in project directory.
Basically, the following files and directory need to be removed.
Reopen the CORE Generator project and the IP does not exist.