1. Buy a socket that fits the 060 which is hard, a 060 CPU which is pritty expencive and a 50Mhz crystal (unless you want to run your 060 overclocked to 66Mhz).
2. Desoldering 040 and solder on 060 socket and insert 060 into it.
3. Somehow install a voltage regulator that supply the 060 with 3.3V instread of 5V. Think there where a extra hardware module you installed on the card to do that (but I would think such a thing is impossible to get at so a custom one will be needed).