Refinance Subprime Mortgage

What should I use to prepare refinance into a fixed-rate loan?
My current mortgage will be reset to an adjustable in the future September I need to know what steps I need to take to possibly refinance into a fixed rate loan. My credit is not shining, and the score is around 600th I have only about $ 2,000 in credit card debt and will pay it out this month. The reason is credit score is so low is because I had high credit card debt that went to collections, but I managed to pay them out in 1999-2001. Someone told me to dispute negative items with credit beareu. I got to know that these negative things are to stay in my credit up to 7 yrs? The clock is ticking and I am so stressed out now I do not know where to start. The lending industry is tightening their lending standards because of subprime misery means I will not be able to refinance and end up losing my house if I can not pay the higher payment? My current rate is 6.35% for 289 000 dollars, what is my payment gonna be after September? I do not think my payment will be doubled to right? Plz HELP!
Just try to apply on a fixed rate loan with one lender, thats the best way to find out if you qualify. Most adjustable loans have an annual cap on the increase. So even if the indexed rate on your loan was 15% this year, it would only be able to go up 2%, or from what it was years before. Contact your current mortgage servicer To find out what your new rate will be.