My brother died he has no wife or children our parents are dead no siblings living but me how do I become legal representative of estate

Please accept my condolences on your loss. It does sound like you are likely the only heir. One question is whether or not your brother had a Will. If he had a Will, then it will likely need to be offered for probate. If he didn't, you will likely need to file a Petition for Letters of Administration. However, before you rush into this on your own, please consider having an experienced probate attorney sit down with you to go over as much as you know about your brother's entire situation. It may be that opening the estate would just expose you to liability risk without much payoff, if he has significant debts. In addition, an attorney's help can make the whole probate and administration process as easy and inexpensive as possible; if you don't have that help you can end up costing yourself more time and money than you might have had to pay otherwise. You might also end up making mistakes that can result in your becoming personally responsible for his debts. If you think you really can't afford an attorney, then at least check with the probate court that would have jurisdiction over your brother's estate: they may have a probate information center staffed by volunteer attorneys that can provide at least some help. One other thing: if the only significant asset in your brother's estate is likely to be the Social Security claim, you may also be able to collect that directly from Social Security as his heir, without having to open the estate. You will need to look into that possibility. Again, having an attorney may help. Best wishes to you.