Balancing disproportionation reactions
It can't be balanced unambiguously, for this is not a single reaction, but a mechanical sum of two reactions, and these can be formally mixed in arbitrary proportion.

The first reaction is indeed a disproportionation. To balance it, use the common trick: consider these two xenons different elements for a while.
$$\ce{\underbrace{XeF2}_{for\;reduction} + \underbrace{XeF2}_{for\;oxidation} +H2O-&gt;Xe + XeO3 + HF}$$
The second is a typical redox:
$$\ce{XeF2 + H2O -&gt; Xe + O2 + HF}$$