Project Weight Loss: Part Deux

Ok, so the FitDay account is set up. It's official, I'm doing this again. My weight as of today is 76.2kg, I'm 5 foot 6 and so my BMI is 27.11 - 25 is considered the top end of healthy. My aim is 59kg (random I know) by April 24th (random I know) this would put my BMI at a much healthier 21. That's just under a kilo a week (about 0.8 if anyone's interested.) I realise that Christmas is slap bang in the middle of this, and that (especially in my house) equals endless amounts of food. But I'm hoping I'll be able to pick up the slack in the new year. So, if anyone wants to do this with me that'd be great or if anyone can recommend an effective diet for vegetarians (I also don't eat egg, but will eat fish) that'd really be a massive help. Fingers crossed for me and my will power!