Originally Posted by BritSteve
If you still have access to the customer side, and have a utility like phpmyadmin, you could probably do the following.
Create a new customer/member account with a password
Make a note of the password you used.
go into phpmyadmin
find the new customrt row.
Copy and paste it into the password field on the admin row.
Log into the admin area using the password you wrote down.
I can't see why this wouldn't work.
There is an improved way which I verified work on version 4.5.0.
1. Create a new customer account
2. Log into phpmyadmin and browse the customer table to locate the record for the newly created customer
3. Change the usertype from C to A for this customer.
4. You can now log into admin using your new user.
5. After your log into admin, change the admin password.