What is the device e.g. 27c512 and is it soldered in or in a socket
Assuming it is in a socket you just need to unplug it, plug it in a universal programmer read the device, plug in your blank EPROM and program it.
I do have a programmer and a wide selection of different types of EPROM. Generally as long as the size is correct you will be OK, but the speed may sometimes be critical, also it is usually better to stick to the same manufacturer as timing differences have been known to cause problems.
Are you sure it is an EPROM and not an EEPROM, most modern kit uses EEPROMs, often built into a microcontroller and therefore very difficult to copy.