I've just bought my daughter a blue Street Ka for her Christmas and I'm having a lot of fun in it till she passes her driving test.

It doesn't have the front fog lamps fitted although these are in the boot, brand new and un-opened.

Had a look at these yesterday and there doesn't appear to be sufficient space to install them from behind. Is it a full bumper off job? If so how is this done?

Shouldn't be. I can only speak about experience I had changing both fog lamps in my wife's StreetKa. Didn't need to take the bumper off, but there are quite a few bolts holding one some plastic trims underneath, all of which around the fog lamps had to be removed. Then getting the lamp in and out was a little bit like a chinese puzzle, but got there in the end. Luckily the plastics are all thin an will bend somewhat, but be careful as don't want to snap the bumper or damage the paint!