1. Find the customer in Shopify that you want to keep. In the URL for that customer, there is a long number at the end, like 1234567890123. Copy that long number into our clipboard so you can use it later.
2. Open the Bloom app and go to Members. I recommend opening this in a new tab and keep your current customer open in the Shopify admin.
3. Find the member you want to use with this customer's info. Click on the Member Details tab where you can see their name, email and phone number. 
4. Change the email to match the one in Shopify you copied the ID from.
5. Paste the ID into the Customer ID field. That field is the "key" that matches a member to a Shopify customer. Do note, you need to make sure the email address and phone number match with the customer you are merging to.