https://support.sonos.com/en-us/article/switch-sonos-between-a-wireless-and-wired-setup

I had did this to switching my play 5 to wireless but it cannot connect

What sort of error message are you seeing?

I suggest that you temporarily wire the PLAY:5 to your network, then make sure that the WiFi credentials are correct.

It can not connect to network via Wifi. Only connect via ethernet cable. I have to try alot to update network for switching wired to wireless, but it can not connect.

Here's reply from Sonos support assistant: 

"

E M

22:56

Thank you for your patience, we did discover an issue your Play:5 Gen 2 speaker, and because of that problem, it is unable to connect to the WiFi. As this is a known issue with the Play:5, we will provide you with a replacement without any costs.

23:03

Please note that we have a limited Play:5 gen 2 inventory in all regions. The replacement you will receive could be a Play:5 (Gen 2) if possible, otherwise you will receive a Sonos Five.

23:04

Please confirm the following details in order for us to update your case:

23:05

- Full Name: - Shipping Address: - Phone Number:

23:05

E M

Are you still here? Please note that if you do not respond, the chat session will automatically end. After the chat ends, you will be provided with a chat transcript which you can download. Please get in touch if you need further assistance and feel free to reference your case number: ********

E M

23:08

Chat Ended from Lost Connection

Close ChatSave Transcript

Moderator edit: removed some details

Seems like you didn’t respond in time, you’re likely going to reconnect, and give them the information they were requesting. You may want to save time and call in. 

I just reconnected. They told that they will replacements an other product fo me.