To add a PhotoID to your GPG key is fairly simple. You'll want to edit your key, and issue the addphoto command.

gpg --edit-key 3C88C6DE

Command> addphoto
Pick an image to use for your photo ID.  The image must be a JPEG file.
Remember that the image is stored within your public key.  If you use a
very large picture, your key will become very large as well!
Keeping the image close to 240x288 is a good size to use.

Enter JPEG filename for photo ID: c:\download\foo2.jpg
Is this photo correct (y/N/q)? y

To delete simply select the sub key, by typing it's number (in this case 2).

pub  1024D/3C88C6DE  created: 2003-10-30 expires: 2007-01-01 trust: -/-
sub  4096g/740F8517  created: 2003-10-30 expires: 2007-01-01
(1). Scott Baker <scott<span>@</span>perturb.org>
(2)* [jpeg image of size 2653]

Command> delphoto
Really remove this user ID? y