Replace page with another PDF file

Question

Suppose i have a complete document containing 100 pages. i want to replace 48th page with another PDF file (just one page). Replacing here means i delete the 48th page and put a new page. That new page is the PDF file that i'm talkng about. I know i can use PDF editor like Adobe Acrobat or anything else, but my point here is what if i need to change my document like revising or adding another page? So, it must be done in the raw document using TeX editor.

Idk if it's necessary, but here's my MWE (it's not 100 pages)

\documentclass[a4paper,12pt,oneside,openany]{book}
\usepackage{pgf, tikz}
\usepackage[a4paper, inner=4cm, outer=3cm, top=4cm, bottom=3cm]{geometry}
\usepackage{geometry}
\usepackage[onehalfspacing]{setspace}
\usepackage{fancyhdr}
\usepackage{titlesec}
\usepackage{setspace}
\usepackage[titles]{tocloft}
\usepackage{tocbibind}
\usepackage{indentfirst}
\usepackage{blindtext}
\usepackage{tocloft}
\usepackage{etoolbox}



\patchcmd{\section}{\bfseries}{\bfseries\boldmath}{}{}
\setlength{\cftbeforesecskip}{10pt}
\setlength{\cftbeforesubsecskip}{10pt}
\fancyhf{}
\cfoot{\thepage}
\linespread{1.5}
\pagestyle{plain}
\renewcommand\cftchapdotsep{\cftdotsep}
\titleformat{\chapter}[block]
{\normalfont\bfseries\centering}
{}{0pt}{}
\titleformat{\section}
{\normalfont\bfseries}
{\thesection}{1em}{}
\titleformat{\subsection}
{\normalfont\bfseries}
{\thesection}{1em}{}
\titlespacing*{\chapter}{0pt}{10pt}{20pt}
\titlespacing*{\section}{0pt}{0pt}{0pt}
\titlespacing*{\subsection}{0pt}{0pt}{0pt}

\renewcommand{\contentsname}{DAFTAR ISI}
\renewcommand{\listtablename}{DAFTAR TABEL}
\renewcommand{\listfigurename}{DAFTAR GAMBAR}

\addtocontents{toc}{\protect\null\protect\hfill{Halaman}\protect\par}
\setlength\parindent{1.25cm} 



\begin{document}
    
    \clearpage
    \thispagestyle{empty}
    \pagenumbering{roman}
    
    \begin{spacing}{0.1}
        \tableofcontents
        \listoffigures
        \listoftables
    \end{spacing}
    \Blinddocument
    
\end{document}

Answer 1

You can use the atbegshi package to tap into the shipout routine. At that stage, the page number is accurate, where you can condition on including something from a different document by placing it in the foregrounds of the current page.

\documentclass{book}

\usepackage{blindtext}
\usepackage{graphicx,atbegshi}

\AtBeginShipout{%
  \ifnum\value{page}=20
    \AtBeginShipoutUpperLeftForeground{%
      \raisebox{-\height}{\includegraphics[page=7]{example-image-letter-numbered}}%
    }%
  \fi
}%

\begin{document}
    
\tableofcontents
\listoffigures
\listoftables

\Blinddocument
    
\end{document}