The Arabs are pretty heavily entrenched by 700, so I'd say it's quite difficult with a POD this late. You could perhaps go down the route of having Basil II be more interested in campaigning in the East than the West, or perhaps by having another soldier Emperor after the 1020s, but the Empire's already had quite a run of good luck with three great Emperors in succession between 963 and 1025, so probably having a fourth would be pushing the bounds of probability somewhat...
The way I did it in IE was to have the Byzantines come in and mop up the remnants after the real heavy work of demolishing the Arab states was done by the Mongols. I'd suggest this may be a way of doing it: perhaps give the Crusaders even more initial success, or have a Norman Kingdom of Egypt or something, which can be absorbed as Byzantine vassals as the twelfth century progresses. This happened IOTL, after all...