Infix can replace a page with a page from another document.
- Open a document whose page you want to replace
- Choose Pages->Replace...
- Choose the document supplying the new page.
- Choose the page from the donor document.
The donor document is unaffected by this operation - a copy of the page is made before insertion into the current document.
- Choose the page to be replaced in the current document.
The chosen page will be permanently deleted.
Make sure you have a backup of the document in case something goes wrong.