No sleep

So my babe is 5.5 months and takes 3 naps a day. Ranging from 15-30 mins every time. His bed time routine starts at 8-8:30 and he’s asleep by 9. But he still wakes up every 2 hours, on the dot, every time. Before the sleep regression he was sleeping 4-6hrs the first stretch n then every 2-3hrs after that.

My question is, do I give him an earlier bed time? I’ve heard that works. Do I cut naps earlier say 3-4 o clock. Do I just let him cry it out.

Help me out pleasee