I installed Studio 1 3 twice how do i uninstall one of them

There is no chance that your Windows Will double / duplicate the same software, unless u install the 32 bit and 64 bit in Windows 64 bit machine. To unistall them go to Start menu, setting, control panel, and Find programs and features. Then select the presonus studio one program, it Will unistall the program. If there is Only one presonus than, u just install the same copy and no double.