i need to beat up someone thats already dead wot do i do

What quest are you stuck on? If your on the PC you can just bypass that stage and move on.

Sounds like Hired Muscle.

Unless you're on PC and there's some way to update the quest via console commands, I'd say you probably have to reload a save from when before you asked for the job. You can try asking for work again and see if you get a different target.

tried wont let me

Did you reload a save from *before* you went and asked for this job? If you just go back looking for a different job, you won't get one while this quest is still active. If you revert to a save from before you asked for work and started this quest, it should solve that problem. Always has for me anyway.

no cant seem to find it :9