It would be extremely contingent upon the attributes of the god concept, but yes it might be possible to completely disprove. Firstly there must be at the very least an acknowledgement that logic can be applied to the god concept (some god concepts do and some god concepts do not have this attribute) and some (specifically non metaphorical) claim made which is directly contravened by another (specifically non metaphorical) claim and the observable state of existence i.e. through a logical examination given certain assertions it is possible to disprove a god concept.
For example
Some god concept which holds itself to be logical
Literally has exactly one eye and this has always been the case and will continue to be the case
Literally has exactly three eyes and this has always been the case and will continue to be the case
Is capable of being proven false.
Of course many god concepts (particularly supernatural ones) do not have logical characterization as an attribute, this immediately means it is impossible to disprove them (actually it means it is also a waste of time to attempt any rational discussion about them, but that is another thread). Likewise many god concepts have a variety of attributed claims, these may have at times been considered literal but believers have been given by their texts etc (or take for themselves) the right to instead adopt metaphorical interpretations of the claims. Metaphorical interpretations provide such a degree of leniency in interpretation, it is functionally impossible to disprove as claims can be interpreted to mean almost anything.