Well I have no problem destroying the fixture but it is now a 2 bulb 48" and I what to make it a 4 bulb 24". The new 24" bulbs will be 96w total and the current 48" bulbs are 108w total.
Will it work?
Im not an expert, but I would say yes. the only thing I would be worried about is if the bulbs would last as long as they should. the extra wattage going through might burn them up faster. someone else will give you better advice on this Im sure
It might light the lamps and work for a while. The current requirement for a 54 watt T5 ho and a 24 watt T5 ho are probably different. You are WAY better off just getting the right ballast. A workhorse 5 costs like 30 bux and while not a true t5 ballast will run the lamps pretty good.