What you should remove from email, when you reply into PGP/INLINE signed email.

Top

From top of the email, remove everything after

-----BEGIN PGP SIGNED MESSAGE-----

untill the first line change.

For example:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

You would remove

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

so the message would be

Hi,

Remove everything between lines

-----BEGIN PGP SIGNATURE-----

and

-----END PGP SIGNATURE-----