What do I need to do to lose ~40-50lbs by August 09'?

I've been biking 30min/day to start.
I'm ~235lbs
Age:17
Height: 5' 8"

I would prefer to keep any exercise to home, as I don't have transportation as of yet. I use an upright stationary bike and there are two 5-lbs. weights lying around.

Last week I got around 50 miles in, I average around 6-7 miles per "workout".

Appreciate any advice that is given. Thanks.

P.S. I'm doing this being I want to have the option of joining AFROTC in August and because it will increase my well-being.

Don't eat bad food. Just stick with organics. Watch the fat in take too.

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