There is nothing like "steps" as such.
1) Create new profile and complete new job bank registration/activation using a new GCKey and new mail id
2) Wait for the profile to be active.
3) Deactivae the Job Bank (old one) profile
4) Delete the old profile
once I delete EE profile from my old GC key, will the old GC key be active? Can I create new profile in the old GC key and connect job bank again with the new profile?
You will have to create a new JB profile as well. There is another small complication here - login to your JB profile and change your email id to something else before deactivating the profile. Your JB profile is linked to an email id and it won't let you use the same mail id to create a new JB profile.
So the steps are:
step 1. change email id in current job bank profile
step 2. deactivate the current job bank profile
step 3. withdraw the current EE profile
step 4. Recreate new EE profile
step 5. create job bank profile and connect to EE profile
So the steps are:
step 1. change email id in current job bank profile
step 2. deactivate the current job bank profile
step 3. withdraw the current EE profile
step 4. Recreate new EE profile
step 5. create job bank profile and connect to EE profile
When you login to your Seeker profile (https://seeker.jobbank.gc.ca/seeker/), activation/deactivation shows up in the right side panel in the middle of the screen.