Yes, you can change it to Zic 5w-30, but keep a close look at the Engine oil level dipstick and if your car is reducing/consuming oil, then I suggest you keep the oil grade to 10w-40 and if not, then keep using it.
I myself am using Caltex Havoline Fully Synthetic 5w30 and I'm pretty satisfied with it.
The rest is your choice. I hope it helps.