Please, please please seek medical advice before you attempt to alter your dosage. Your doctor may be able to switch your medication and re-evaluate your circumstances.
The reason I urge you to be so cautious is because when a good friend decided to lower her dosage slowly because she felt it was more of a hindrance than a help to her well being, it had really disasterous effects and put back her recovery time significantly.
If your doctor isn't particularly helpful, you have the right to ask to be referred to a specialist or a therapist than can spend the time to find out why you want to wean yourself off, offer you guidance and support, and maybe even alter the dosage themselves, thus reassuring you that you're making the right decision.
This is not so much a tip about how to come off prozac specifically, but a warning about all SSRI's. GP's are all to ready to hand them out. I had a long history of depressive illness and was given fluoxetine and I was very unwell with manic symptoms and it was found that I had an allergy to the serotonin levels in my system. If you are on any of these drugs you must have medical supervision on withdrawal because they need to make sure that your depressive problems have stabilised enough for you to come off them or incase you need additional support during the change. It must also be done gradually as Cold-turkey can lead to severe physical and psychological side effects. If possible try to get non-drug therapy when withdrawing, it can help if you persevere :)
I'm about to start weaning myself off citalopram, another SSRI. I feel very lucky to have a fabulous GP who has helped me through a tough couple of years, and I'm doing it by her advice.
I'm anxious about not realising I've slipped backwards, until I've slipped a long way. I'm planning to write a few sentences each day in summary of how I'm feeling.
Finally, don't start it at a time when there is unusual stress around you. Wait until you feel good, really good. Then wait another 4 months or so before reducing.
Finally finally! alert either your best friend / partner/ spouse / parent / sibling that you are starting to change your meds. That way they will be conscious of your moods and any persistent down periods.
I went on a cognitive behavioural therapy course around six months ago. The stuff in it wasn't ground breaking but it was really useful. I then went down to half strength and have been for four or five months. I am going down to half of that again in a few weeks. I've been ok but I really think it's the positive thinking from the course that's helped. Worth asking your doc if there's a course you could go to.
My sister has been trying to come off of seroxat, she struggled with dizziness when reducing tablets under her doctors instruction. She has now been given it in a liquid form and is finding it a lot easier to titrate.