Current on AP mode for 6 X50-PoE via a 1218MPE switch, powered via PoE with a 1G fibre broadband.

ISP obsoleting 1G plan and now minimum is 2G. 
 

question is how do I keep using X50-PoE, take advantage of 2.5G port and capability while powered via PoE? 
 

limitation:All AP are already ceiling mounted and there are no provision of power point next to each unit, so only PoE is possible.

ok to change switch, but keep using X50.

any advice ?