before replace Bluetooth and WiFi try these:
Make sure you turn off Wi-Fi or Bluetooth, wait a few seconds and turn it back on. If that doesn't fix the problem, head to the next step.
Restart your phone. Sometimes all that's needed a quick kick to the reset button and you're good to go.
If Wi-Fi problems persist, try forgetting the network by long pressing on the network name and tapping Forget network. Then tap the network again to re-enter the password and re-connect.
If Bluetooth problems persist, try unpairing the device from your phone and re-pairing. To do that, tap on the cog icon next to the product's name and hit Unpair. Put the device you're connecting to in pairing mode and connect again.
If you're worried you may have tweaked settings inadvertently and want to start over, go to General management, Reset and then tap Reset network settings