How to lose weight for my 10 Yr HS Reunion Advice?

I found out today that my 10 yrs HS Reunion will take place around Thanksgiving of 2010,

Right now Im 290 5’8

When I graduated I was about 215

How much weight can I lose?

I’d like to be 190 or under advice?

I want to blow everyone away.

I want it to be the ultimate revenge haha