I have a small script where I want to see if a file exists & then delete the first line from it.

I have code to help me find if the file exists, but I am unsure as to how to then take in the answer and remove the first line from the flatfile:

This is what I have so far just to output if the file exists:

for a in $(cat ~/scripts/test.txt)
do

if [ -f $DEST/$a ]
then
echo file $a exists >> ~/scripts/test2.txt
else
echo file $a does not exist >> ~/scripts/test3.txt
fi
done