I have a WP single install site at MYSITE.com/subdomain1/website1
I want to create a WP Multisite at MYSITE.com
After creating the WP Multisite MYSITE.com I want to migrate MYSITE.com/subdomain1/website1 to the WP Multisite including all of its plugins, Membership (plugin) data, databases etc.
1) Please give the clear step by step method to do this
2) Please give the steps to backup the single user site described above
Thanks in advance