How to Paste photo in pdf file at specific postion (using gimp)

Pdf viewer only allows to view files, but not to edit them say if you fill up pdf or paste photo in photo box it won't be possible

Suppose required to paste photo in photo box located in pdf file say in pg 2.

For this split pdf in pages -> import pf2.pdff in gimp -> open photo as layer in gimp

-> GIMP_menuBar {Tools > Transform Tools > Scale}->resize photo to required size -> click scale

-> Move photo do desired position using Move tool

->  [ crop photo if necessary, do adjustments needed in photo as requried]

-> Rt click on photo layer -> Merge_Down

-> File export as pdf

Now exported file will be the reqd pdf pg2 as needed

Merge pdf pages back using pdfunite

$pdfunite pg1.pdf pg2.pdf ... pgn.pdf output.pdf

DONE!