Upload new footer question.

I have a WP blog and the template footer was coded with the designers
anchor text. I've now had that decoded and replaced his with my text.
Can I now ftp this up and replace the footer that is there at present without
it going all messy on me?

The only way to check this is by making backup copy and uploading your new footer

You should also remember that wordpress themes are pretty mostly editable inside Wp-admin and dont need to depend on the ftp at most