Adaption of an purchased robot to a new mt4 build

Hi,

some years ago, i got an expert advisor which worked very well, but now, since the new mt4 build appeared, the robot doesnt work anymore and the seller isn't available anymore. 

Can anybody help me please and can make this robot run on the newest mt4 build?

Let me know, how much this job cost and i will adapt the payment.

Thank you and kind regards,

Emanuel