Note, you can't reset password if the customer account status is not active.;

Method #1: Reset customer password from dashboard

Step 1: Go to Customers

After logging in and accessing Shopify admin interface, take a look at the menu list on the left side of the screen. At there, you will have to click Customers.

Step 2: Select your customer

By clicking Customers, a list of customers will appear. In here, you can select a customer who needs to reset the password.

Step 3: Reset password

After choosing your customer, you will be directed to a page showing all information relevant to the selected customer. In order to reset the password, you have to click on More Actions dropdown. You can easily find it. To customers who have not activated account yet, the Reset password line will not be showing in dropdown list. After clicking on the line, the Reset password window will appear. Click Reset password button at the bottom of the window to confirm, and an email will be sent to the selected customer with instructions right after.

Method #2: Reset customers password from store login page

Step 1: Go to Login Page

After open store, go to Login page [ /accounts/login].

Step 2: Click on Forgot your password?

Click on Forgot your password? link, that will showing below password field.

Step 3: Submit Email

After Clicking on Forgot your password? link, winodw popup will be showing on which you required to enter registered email. After entering the email, submit it . then an email will be sent to the selected customer with instructions right after.