help and advice . modifying or selling and buying another

[firemids]

Hi I'm hoping some one on here can help or perhaps just advice best corse of action. I'm running a crystalyte hs3540 with a grin tech infineon XC846. I'm running 75 volts but would really like to run 100v ( not for massive distances , so I won't cook it ) . My question is . Is it easy to modify this controller and can anyone talk me through it or would it be best to sell this one and add a few pound more and buy another controller ? Kind regards paul