The FX 6300 uses a socket AM3+, whilst am A10 6800 uses a socket FM2. So if you want to change the CPU only, it is not possible to go from a FX 6300 to a A10 6800 because they use other sockets, and are not compatible. You will need to also change the motherboard.
Also, the A10 is not much of an upgrade, I would say more of a downgrade compared to the FX 6300. It has less cores, though it clocks higher. But the FX can be easily overclocked.