How to do decrypt a pgp message

After sending my public pgp key and getting an encoded message back. I need to decrypt a pgp message.

I made a pgp file by opening a text editor and saving it as "mypgpfile.pgp"

gpg -o output.txt mypgpfile.pgp  

The breakdown:
gpg - the command to encode/decode pgp on linux. Package may need to be installed.
-o - specifies the output file
output.txt - the output filename
mypgpfile.pgp - the input encoded message